Deck 2: Force

Question 1

An airplane is flying in horizontal flight at a constant velocity.The weight of the airplane is 40,000 N.The wings produce a lift force that is perpendicular to the wings and a drag force that is parallel to the wing.The engine produces a forward thrust force of 2,000 N.Which of the following statements is true?

A) the net force on the airplane is zero
B) the net force on the airplane is forward
C) the net force on the airplane is upward
D) the net force on the airplane is downward
E) the net force on the airplane is backward

Answer 1

the net force on the airplane is zero

Question 2

In the figure an airport luggage carrying train with a tractor T is pulling three luggage carts,M₁,M₂,and M₃,with constant velocity of 4.5 m/s.If T = 300.0 kg,M₁ = 200.0 kg,M₂ = 100.0 kg,and M₃ = 100.0 kg,and the coefficient of kinetic friction for each is 0.4000,what is the force in the connection between the tractor T and cart M₁?

A) 2941 N
B) 2744 N
C) 1568 N
D) 1862 N
E) 2439 N

Answer 2

1568 N

Question 3

If an object of mass 20 kg on earth is sent to the moon it will have a mass of

A) 10 kg.
B) 20 kg.
C) 0.0 kg.
D) 4.0 kg.

Answer 3

20 kg.

Question 4

A man who weighs 600 N is sitting in a chair with his feet on the floor and arms resting on the armrests.The chair weighs 100 N.Each armrest exerts an upward force of 25.0 N on his arms,and the seat exerts an upward force of 500 N.What force does the floor exert on his feet?

A) 75 N upward
B) 500 N upward
C) 525 N upward
D) 50 N upward
E) 0 N

Question 5

A car is driving on a level highway.It is acted upon by the following forces: a downward gravitational force of 12 kN,an upward contact force due to the road of 12 kN,another contact force due to the road of 7 kN directed West,and a drag force due to air resistance of 5 kN directed East.What is the net force acting on the car?

A) 7 kN East
B) 24 kN up
C) 2 kN West
D) 5 kN East
E) 2 kN East

Question 6

A freight train consists of an engine and several identical cars on a level track.Which of the following statements is true?

A) if the train is moving at constant speed,the engine must be pulling with a force greater than the train's weight
B) if the train is moving at constant speed,the engine's pull on the first car must exceed that car's backward pull on the engine
C) if the train is coasting,its inertia makes it slow down and eventually stop
D) if the train is moving at constant speed the engine's pull must be equal to the friction

Question 7

The force that causes an object to fall to earth is

A) gravitational force.
B) electromagnetic force.
C) weak interaction.
D) strong nuclear force.

Question 8

An airplane is flying in horizontal flight at a constant velocity.The weight of the airplane is 40,000 N.The wings produce a lift force that is perpendicular to the wings and a drag force that is parallel to the wing.The engine produces a forward thrust force of 2,000 N.Which of the following statements is true?

A) the lift force on the airplane is zero
B) the drag force on the airplane is zero
C) the lift force on the airplane is 42,000 N upward
D) the drag force on the airplane is 38,000 N downward
E) the drag force on the airplane is 2,000 N backward

Question 9

When a person stands on a scale,which of the following is not a force exerted on the scale?

A) a contact force due to the floor
B) a contact force due to the person's feet
C) the weight of the person
D) the weight of the scale

Question 10

The force that holds charged atoms together is

A) gravitational force.
B) electromagnetic force.
C) weak interaction.
D) strong nuclear forces.

Question 11

The force that holds the nucleus together is

A) gravitational force.
B) electromagnetic force.
C) weak interaction.
D) strong nuclear force.

Question 12

An airplane is traveling in level flight at a constant velocity.L is the lift,W is the weight,T is the thrust,and D is the drag.Which of the diagrams is the correct free body force diagram for the airplane?

A) Figure 1
B) Figure 2
C) Figure 3
D) Figure 4
E) Figure 5

Question 13

A 20-kg sack of potatoes at the corner store weighs

A) 190 pounds.
B) 150 pounds.
C) 44 pounds.
D) 9.9 pounds.

Question 14

Which of the following is a vector quantity?

A) volume
B) force
C) speed
D) time
E) length

Question 15

A rock of weight 17.5 N is immersed in a beaker of water while suspended from a spring scale with a reading of 9.00 N.The weight of the beaker and water together is 23.5 N.What is the net force of the beaker on the table?

A) 17.5 N
B) 23.5 N
C) 32.0 N
D) 41.0 N

Question 16

Three objects experience interactions.Object A has mass,object B has electrical charge,and object C has both mass and electrical charge.Object A and object B have a rope connected between them.Which of the following statements are true?

A) the electrical force on A due to B has the same magnitude as the gravitational force on B due to A
B) the gravitational force on C due to A has the same magnitude as the gravitational force on A due to C
C) the rope force on A due to B has the same magnitude as the electrical force on B due to A
D) the rope force on B due to A has the same magnitude as the gravitational force on A due to C

Question 17

A person weighs 146 pounds.The person's weight is (1 lb = 4.45 N)

A) 445 N.
B) 500 N.
C) 584 N.
D) 650 N.

Question 18

Three objects experience interactions.Object A has mass,object B has electrical charge,and object C has both mass and electrical charge.Which of the following statements are true?

A) object A and object B experience an electrical interaction
B) object A and object C experience a gravitational interaction
C) object C experiences an electrical interaction with itself
D) object A and object C experience an electrical interaction
E) object A and object B experience a gravitational interaction

Question 19

The net force on a moving object suddenly becomes zero.The object then

A) stops abruptly.
B) stops during a short time interval.
C) changes direction.
D) continues at constant velocity.
E) slows down gradually.

Question 20

A person weighs 155 pounds.What is the person's weight in Newtons?

A) 155 N
B) 689 N
C) 39.3 N
D) 392 N

Question 21

The gravitational field on the surface of the earth is (G = 6.67 $\times$ 10^-11 N m²/kg²,mass of the earth is 5.98 $\times$ 10²⁴ kg,radius of the earth is 6.38 $\times$ 10⁶ meters)

A) 3.40 N/kg.
B) 6.20 N/kg.
C) 9.80 N/kg.
D) 10.1 N/kg.
E) 20.3 N/kg.

Question 22

A space probe leaves the solar system to explore interstellar space.Once it is far from any stars,when must it fire its rocket engines?

A) all the time,in order to keep moving
B) only when it wants to speed up
C) only when it wants to slow down
D) only when it wants to turn
E) when it wants to speed up,slow down,or turn

Question 23

Given that a vector extends from the origin to (-5.0 cm,8.0 cm),find the magnitude of the vector.

A) 9.8 cm
B) 3.4 cm
C) 9.4 cm
D) -5.6 cm

Question 24

Vector A has a magnitude of 3.0 units and makes an angle of $-90.0^{\circ}$ with the positive x-axis.Vector B has a magnitude of 4.0 units and makes an angle of $-120^{\circ}$ with the positive x-axis.What is the magnitude of the vector sum of A + B?

A) 1.0 units
B) 6.8 units
C) 4.0 units
D) -6.8 units

Question 25

Given that a vector extends from the origin to (-5.0 cm,8.0 cm),find the direction of the vector from the positive x-axis.

A) $32^{\circ}$
B) $58^{\circ}$
C) $148^{\circ}$
D) $122^{\circ}$

Question 26

A large massive rock is in contact with the earth.Draw a force diagram for the rock and the earth.Which of the following statements is true?

A) The gravitational force on the rock due to the earth and the gravitational force on the earth due to the rock are interaction partners.
B) The gravitational force on the rock due to the earth and the contact force on the earth due to the rock are interaction partners.
C) The contact force on the earth due to the rock and the gravitational force on the earth due to the rock are interaction partners.
D) The gravitational force on the earth due to the rock and the contact force on the earth due to the rock are interaction partners.

Question 27

If you add two vectors with magnitudes of 200 and 40,which of the following is the only possible resultant?

A) 100
B) 260
C) 0
D) 200
E) 40

Question 28

Interaction partners

A) are equal in magnitude and opposite in direction and act on the same object.
B) are equal in magnitude and opposite in direction and act on different objects.
C) appear in a free-body diagram for a given object.
D) always involve gravitational force as one partner.
E) act in the same direction on the same object.

Question 29

When an object is in translational equilibrium,which of these statements is not true?

A) the vector sum of the forces acting on the object is zero
B) the object must be stationary
C) the object has a constant velocity
D) the speed of the object is a constant

Question 30

A force of 15 N toward the WEST is applied to a 4.0 kg box.Another force of 42 N toward the EAST is also applied to the 4.0 kg box.The net force on the 4.0 kg box is

A) 57 N toward the WEST.
B) 27 N toward the EAST.
C) 36 N toward the WEST.
D) 36 N toward the EAST.
E) 17 N toward the WEST.

Question 31

The gravitational field at a satellite that is orbiting about the earth at an altitude of 5,000 km is (G = 6.67 $\times$ 10^-11 N m²/kg²,the mass of the earth is 5.98 $\times$ 10²⁴ kg)

A) 9.55 N/kg.
B) 8.43 N/kg.
C) 3.08 N/kg.
D) 6.33 N/kg.
E) 5.28 N/kg.

Question 32

Given that a force vector extends from the origin to (120 N,-60.0 N),find the magnitude of the vector.

A) 140 N
B) 134 N
C) 180 N
D) 60.0 N

Question 33

Given that a force vector extends from the origin to (120 N,-60.0 N),find the direction of the vector referenced to the positive x-axis.

A) $116^{\circ}$
B) $26.6^{\circ}$
C) $-26.6^{\circ}$
D) $122^{\circ}$

Question 34

Causing an object to start moving on a frictional surface requires

A) less force than is needed to keep it moving on the surface.
B) the same force as is needed to keep it moving on the surface.
C) more force than is needed to keep it moving on the surface.
D) a force equal to the weight of the object.
E) a force opposite to the normal force.

Question 35

A mass sits at rest on top of a table.Which two forces are interaction pair forces and thus are equal and opposite?

A) the force of gravity on the mass due to the earth and the force of gravity on the earth due to the mass
B) the force of gravity on the mass due to the earth and the contact force on the table due to the mass
C) the contact force on the mass due to the table and the force of gravity on the earth due to the mass
D) the force of gravity on the mass due to the earth and the contact force on the mass due to the table

Question 36

Five children are pushing on a snowball; each is pushing with a force of 10.0 N.Each is pushing at an angle of $45^{\circ}$ relative to his neighbor.What is the net push on the ball?

A) 0 N
B) 24.1 N
C) 27.1 N
D) 17 N
E) 50 N

Question 37

Vector A has a magnitude of 3.0 units and makes an angle of $-90.0^{\circ}$ with the positive x-axis.Vector B has a magnitude of 4.0 units and makes an angle of $-120^{\circ}$ with the positive x-axis.What is the direction of the vector sum of A + B referenced to the positive x-axis?

A) $-107^{\circ}$
B) $55^{\circ}$
C) $-55^{\circ}$
D) $-145^{\circ}$

Question 38

Diane (weight 255 N)is practicing on a tightrope that is 6.00 meters long and sags by 0.120 meters.When she is in the middle of the rope,what is the force on each eyebolt holding the tightrope?

A) 1.62 $\times$ 10³ N
B) 3.19 $\times$ 10³ N
C) 6.38 $\times$ 10³ N
D) 4.99 $\times$ 10³ N

Question 39

The diagram below represents an ideal pulley system (no mass or friction).What is the force required to lift the 45 kg mass?

A) 442 N
B) 393 N
C) 221 N
D) 147 N

Question 40

In the figure,an airport luggage carrying train with a tractor T is pulling three luggage carts,M₁,M₂,and M₃.with constant velocity of 4.5 m/s.If T = 300 kg,M₁ = 200 kg,M₂ = 100 kg,and M₃ = 100 kg (there is no friction),then the force in the connection between the tractor T and cart M₁ is

A) 980 N.
B) 560 N.
C) 280 N.
D) 140 N.
E) 0.00 N.

Question 41

The weight of a 1.00 kg on the surface of the moon is (G = 6.67 $\times$ 10^-11 N m²/kg²,R of the moon is 1.74 $\times$ 10⁶ m,mass of the moon is 7.35 $\times$ 10²² kg)

A) 9.80 N.
B) 7.59 N.
C) 1.62 N.
D) 0.981 N.
E) 0.548 N.

Question 42

A box that weighs 300 N is pulled across a level surface with a constant velocity.The rope makes an angle of 30.0 degree above the horizontal and the tension in the rope is 100 N.What is the normal force of the floor on the box?

A) 86 N
B) 300 N
C) 50 N
D) 250 N
E) 0 N

Question 43

The gravitational field at the moon due to the earth is (the mass of the earth is 5.98 $\times$ 10²⁴ kg,the distance to the moon is 3.85 $\times$ 10⁸ m)

A) 2.69 $\times$ 10^-3 N/kg toward the earth.
B) 2.69 $\times$ 10^-3 N/kg away from the earth.
C) 7.30 $\times$ 10^-3 N/kg away from the earth.
D) 7.30 $\times$ 10^-3 N/kg toward the earth.
E) 5.00 $\times$ 10^-3 N/kg toward the earth.

Question 44

What is the gravitational force between two nuclei,each of mass 3.20 $\times$ 10^-27 kg and separated by a distance of 10.6 $\times$ 10^-11 m? (G = 6.67 $\times$ 10^-11 N m²/kg²)

A) 6.08 $\times$ 10^-45 N
B) 6.08 $\times$ 10^-44 N
C) 6.08 $\times$ 10^-43 N
D) 6.08 $\times$ 10^-42 N

Question 45

What is the gravitational force between two 5.00 kg masses that are 10.0 cm apart from center to center? (G = 6.67 $\times$ 10^-11 N m²/kg²)

A) 1.67 $\times$ 10^-8 N
B) 1.67 $\times$ 10^-7 N
C) 1.62 $\times$ 10^-6 N
D) 1.62 $\times$ 10^-5 N
E) 1.67 $\times$ 10^-4 N

Question 46

A 750 N box rests on a floor with a coefficient of static friction = 0.800 and coefficient of kinetic friction = 0.600.What is the force of friction if a horizontal force of 550 N is applied to the box?

A) 600 N
B) 450 N
C) 750 N
D) 550 N
E) 440 N

Question 47

The tallest spot on Earth is Mt.Everest,which is 8850 m above sea level.If the radius of the Earth to sea level is 6370 km,how much does the magnitude of g change between sea level and the top of Mt.Everest?

A) 0.0030 m/s²
B) 0.020 m/s²
C) 0.035 m/s²
D) 0.025 m/s²
E) 0.030 m/s²

Question 48

When a force is called a "normal" force,it is

A) the usual force expected given the arrangement of a system.
B) a force that is perpendicular to the surface of the Earth at any given location.
C) a force that is always vertical.
D) a contact force perpendicular to the contact surfaces between two solid objects.
E) the net force acting on a system.

Question 49

A mass sits at rest on top of a table.Which two forces that are not action-reaction pair forces are equal and opposite?

A) the force of gravity on the mass due to the earth and the force of gravity on the earth due to the mass
B) the contact force on the mass due to the table and the contact force on the table due to the mass
C) the force of gravity on the mass due to the earth and the contact force on the table due to the mass
D) the force of gravity on the mass due to the earth and the contact force on the mass due to the table
E) the contact force on the mass due to the table and the force of gravity on the earth due to the mass

Question 50

Within a given system,the internal forces

A) are always balanced by the external forces.
B) all add to zero.
C) are only determined by subtracting the external forces from the net force on the system.
D) determine the motion of the system.
E) are measured with a gravimeter.

Question 51

An object with a mass of 200.0 kg is 500.0 Km above the surface of the earth.The force of gravity on the 200.0 kg mass is (G = 6.67 $\times$ 10^-11 N m²/kg²,radius of the earth is 6.38 $\times$ 10⁶ m,mass of earth is 5.98 $\times$ 10²⁴ kg)

A) 2.02 $\times$ 10³ N.
B) 1.69 $\times$ 10³ N.
C) 1.42 $\times$ 10³ N.
D) 1.28 $\times$ 10³ N.
E) 1.05 $\times$ 10³ N.

Question 52

A block is at rest on a wooden ramp.The coefficient of static friction between the block and ramp is 0.35.What is the angle between the ramp and the horizontal direction when the box first begins to slide?

A) $17^{\circ}$
B) $19^{\circ}$
C) $29^{\circ}$
D) $20^{\circ}$
E) $22^{\circ}$

Question 53

A friction force

A) is a contact force that acts parallel to the contact surfaces.
B) is a normal force between contact surfaces.
C) is a scalar quantity since it can act in any direction along a surface.
D) does not depend on the nature of the surfaces.

Question 54

A 755 N box rests on a floor with a coefficient of kinetic friction of 0.600 and a coefficient of static friction of 0.800.What horizontal force is required to start the box moving?

A) 755 N
B) 453 N
C) 254 N
D) 653 N
E) 604 N

Question 55

The moon with a mass of 7.35 $\times$ 10²² kg is orbiting about the earth with a mass of 5.98 $\times$ 10²⁴ kg at a radius of 3.85 $\times$ 10⁸ meters.The earth is orbiting about the sun with a mass of 1.99 $\times$ 10³⁰ kg at a radius of 1.50 $\times$ 10¹¹ meters.The force of gravity on the moon when it is between the earth and the sun is (G = 6.67 $\times$ 10^-11 N m²/kg²)

A) 4.36 $\times$ 10²⁰ N toward the sun.
B) 4.36 $\times$ 10²⁰ N toward the earth.
C) 2.36 $\times$ 10²⁰ N toward the sun.
D) 2.38 $\times$ 10²⁰ N toward the earth.
E) 1.98 $\times$ 10²⁰ N toward the earth.

Question 56

A 750 N box moves at a constant velocity on a floor with a coefficient of static friction = 0.800 and coefficient of kinetic friction = 0.600.What horizontal force is required to keep the box moving?

A) 600 N
B) 550 N
C) 500 N
D) 450 N
E) 750 N

Question 57

The moon with a mass of 7.35 $\times$ 10²² kg is orbiting about the earth with a mass of 5.98 $\times$ 10²⁴ kg at a radius of 3.85 $\times$ 10⁸ meters.The force of gravity on the moon due to the earth is (G = 6.67 $\times$ 10^-11 N m²/kg²)

A) 9.20 $\times$ 10³⁰ N.
B) 3.20 $\times$ 10²⁸ N.
C) 6.70 $\times$ 10²⁴ N.
D) 1.98 $\times$ 10²⁰ N.
E) 4.10 $\times$ 10¹² N.

Question 58

The gravitational field at the earth due to the moon is (the mass of the moon is 7.35 $\times$ 10²² kg,the distance to the moon is 3.85 $\times$ 10⁸ m)

A) 2.90 $\times$ 10^-5 N/kg toward the moon.
B) 3.31 $\times$ 10^-5 N/kg away from the earth.
C) 4.01 $\times$ 10^-5 N/kg toward the moon.
D) 5.91 $\times$ 10^-5 N/kg away from the earth.
E) 7.50 $\times$ 10^-5 N/kg toward the moon.

Question 59

The moon with a mass of 7.35 $\times$ 10²² kg is orbiting about the earth with a mass of 5.98 $\times$ 10²⁴ kg at a radius of 3.85 $\times$ 10⁸ meters.The earth is orbiting about the sun with a mass of 1.99 $\times$ 10³⁰ kg at a radius of 1.50 $\times$ 10¹¹ meters.The gravitational field on the moon due to the earth and the sun when it is between them is (G = 6.67 $\times$ 10^-11 N m²/kg²)

A) 5.93 $\times$ 10^-3 N/kg toward the sun.
B) 5.93 $\times$ 10^-3 N/kg toward the earth.
C) 3.21 $\times$ 10^-3 N/kg toward the sun.
D) 3.21 $\times$ 10^-3 N/kg toward the earth.
E) 2.69 $\times$ 10^-3 N/kg toward the earth.

Question 60

A boy with a mass of 55 kg walks into a room and sees a girl 8.0 m in front of him who has a mass of 40 kg.What is his gravitational attraction to her?

A) 2.0 $\times$ 10⁸ N
B) 2.3 $\times$ 10^-9 N
C) 2.2 $\times$ 10^-11N
D) 2.4 $\times$ 10^-8 N
E) 2.1 $\times$ 10⁹ N

Question 61

A 120 N traffic light is located at the midpoint of a cable between two poles.The cable makes and angle of $30^{\circ}$ to the horizontal at each pole.What is the tension in the cable?

A) 60.0 N
B) 90.0 N
C) 140 N
D) 110 N
E) 120 N

Question 62

In order to slide a 70.0 kg box across the floor at a constant speed,you must push horizontally with a force of 351 N.What is the coefficient of kinetic friction?

A) 0.149
B) 0.584
C) 0.337
D) 0.512
E) 0.678

Question 63

The fundamental force that has the shortest range is

A) strong force.
B) weak force.
C) electromagnetic force.
D) gravitational force.

Question 64

The fundamental force that binds the electrons to the nuclei to form atoms is

A) strong force.
B) weak force.
C) electromagnetic force.
D) gravitational force.

Question 65

An airplane flies at a constant speed at an angle of 25 degrees above the horizontal.Which statement below is not true?

A) The net force on the plane is zero.
B) The lift is the same magnitude as the weight.
C) The plane has a constant velocity.
D) The thrust is greater in magnitude than the drag.

Question 66

The fundamental force that is the weakest of the four is

A) strong force.
B) weak force.
C) electromagnetic force.
D) gravitational force.

Question 67

In order to slide a 753 N box across the floor at a constant speed,you must push horizontally with a force of 452 N.What is the coefficient of kinetic friction?

A) 1.66
B) 0.600
C) 0.660
D) 0.580
E) 1.65

Question 68

One person holds a spring scale while another pulls until the scale reads 32 N.What is the force that the person holding the scale applies?

A) 32 N
B) 16 N
C) 64 N
D) 48 N
E) 0.0 N

Question 69

Using an angle of $~30^{\circ}$ to supply the force required to slide a box along a floor with a coefficient of friction of 0.30,which would require the least force to move it?

A) pull it with a rope
B) push it
C) either push or pull
D) not enough information to solve

Question 70

A 90.0 N crate of apples sits at rest on a ramp that runs from the ground to the bed of a truck.The ramp is inclined at $20^{\circ}$ to the ground.What is the force exerted on the crate by the ramp?

A) 86.9 N
B) 84.6 N
C) 75.8 N
D) 30.8 N
E) 38.5 N

Question 71

A force of 451 N is applied to 111 kg box that has a coefficient of static friction of 0.450.What is the force of friction on the box?

A) 490 N
B) 0.00 N
C) 108 N
D) 451 N
E) 203 N

Question 72

A force of 3.8N directed along the positive x-axis combines with a second force directed along the positive y-axis to produce a total force vector of magnitude 6.1N.What is the magnitude of the second vector?

A) 2.7N
B) 9.5N
C) 23.5N
D) 4.8N
E) Not enough information is given.

Question 73

The y-component of a force vector is -15.0N,while its magnitude is 27.2N.Which could be the vector's direction?

A) $61.1^{\circ}$ below the +x axis
B) $56.5^{\circ}$ below the -x axis
C) $33.5^{\circ}$ below the -x axis
D) $28.9^{\circ}$ below the +x axis
E) None of the choices are correct.

Question 74

The fundamental force that governs the motion of the planets is

A) strong force.
B) weak force.
C) electromagnetic force.
D) gravitational force.

Question 75

A force of 15.2N directed along the positive x-axis combines with a second force to produce a total force vector of magnitude 17.9N.What is the magnitude of the second vector?

A) 2.7N
B) 9.5N
C) 23.5N
D) Not enough information is given.

Question 76

An airplane flies at a constant speed at an angle of 25 degrees below the horizontal.Which statement below is not true?

A) The thrust is greater in magnitude than the drag.
B) The weight is greater in magnitude than the lift.
C) The net force on the plane is zero
D) The plane has constant velocity.

Question 77

A box is pushed across a horizontal table at constant speed.Of the forces on it,which pair do we know are equal in magnitude because of Newton's third law?

A) Normal force on the box and the weight of the box.
B) Normal force on the box and the normal force on the table by the box.
C) The force of kinetic friction on the box and the force applied to the box by the one pushing it.
D) None of these are interaction pairs.

Question 78

A rope is connected to a scale on the left and exerts a force T₁ and a rope is connected to the same scale on the right and exerts a force T_2. The scale shows a reading of T_s = 120 N.The values of T₁ and T₂ are

A) T₁ = 80 N,and T₂ = 80 N.
B) T₁ = 120 N,and T₂ = 120 N.
C) T₁ = 240 N,and T₂ = 240 N.
D) T₁ = 80 N,and T₂ = 120 N.

Question 79

A box weighing 550N slides at constant speed across a flat parking lot,under the influence of a stiff wind.The wind applies a force of 155N parallel to the surface of the parking lot.What is the angle relative to the vertical of the contact force applied by the ground.

A) 75 $^{\circ}$
B) 74 $^{\circ}$
C) 90 $^{\circ}$
D) 16 $^{\circ}$
E) 15 $^{\circ}$

Question 80

A sled weighs 10.0 kg It is held in place on a frictionless 20.0 degree slope by a rope attached to a stake at the top of the slope.Find the tension in the rope if it is parallel to the slope.

A) 47.9 N
B) 37.4 N
C) 94.1 N
D) 33.5 N
E) 23.8 N