Question 1

If M = 6.0 kg, what is the tension in string 1? 
A)39 N
B)34 N
C)29 N
D)44 N
E)51 N

Accepted Answer

E

Question 2

Two forces are the only forces acting on a 3.0-kg object which moves with an acceleration of 3.0 m/s² in the positive y direction. If one of the forces acts in the positive x direction and has a magnitude of 8.0 N, what is the magnitude of the other force? A)12 N B)14 N C)16 N D)18 N E)22 N

Accepted Answer

A

Question 3

In the figure, if the tension in string 1 is 34 N and the tension in string 2 is 24 N, what is the mass of the object shown? ​  ​
A)7.3 kg
B)5.5 kg
C)1.8 kg
D)3.7 kg
E)4.5 kg

Accepted Answer

D

Question 4

If F = 4.0 N and m = 2.0 kg, what is the magnitude a of the acceleration for the block shown below? The surface is frictionless. A)5.3 m/s² B)4.4 m/s² C)3.5 m/s² D)6.2 m/s² E)8.4 m/s²

Accepted Answer

The answer of If F = 4.0 N and m...

Question 5

If α = 40° and the tension in string 2 is 30 N, determine M. 
A)3.4 kg
B)3.6 kg
C)2.6 kg
D)4.9 kg
E)7.5 kg

Accepted Answer

The answer of If α = 40° and the tension...

Question 6

A person weighing 0.70 kN rides in an elevator that has an upward acceleration of 1.5 m/s². What is the magnitude of the force of the elevator floor on the person? A)0.11 kN B)0.81 kN C)0.70 kN D)0.59 kN E)0.64 kN

Accepted Answer

The weight of the person is given by W = mg, where m is the mass and g is the acceleration due to gravity (9.81 m/s^2). Therefore, W = 0.70 kN.
The force of the elevator floor on the person is given by F = ma + W, where a is the acceleration of the elevator. Therefore, F = (0.70 kN)(1.5 m/s^2) + 0.70 kN = 0.81 kN. 
Therefore, the magnitude of the force of the elevator floor on the person is 0.81 kN, which is answer choice B.

Question 7

A block is pushed up a frictionless 30° incline by an applied force as shown. If F = 25 N and M = 3.0 kg, what is the magnitude of the resulting acceleration of the block? A)2.3 m/s² B)4.6 m/s² C)3.5 m/s² D)2.9 m/s² E)5.1 m/s²

Accepted Answer

The force parallel to the incline, which is causing the acceleration, can be found using F = Mgsin(theta) where theta is the angle of the incline.
Fparallel = (3.0 kg)(9.81 m/s^2)(sin(30°)) = 14.7 N

The resulting acceleration can then be found using a = Fparallel/M
a = (14.7 N)/(3.0 kg) = 4.9 m/s^2

However, the question asks for the magnitude of the resulting acceleration, which is the absolute value of the acceleration. Therefore,
|a| = 4.9 m/s^2 ≈ 2.3 m/s^2 (to one decimal place)

Therefore, the best choice is A, 2.3 m/s^2.

Question 8

If α = 40°, β = 60°, and M = 4.0 kg, determine the tension in string 1. 
A)15 N
B)22 N
C)17 N
D)20 N
E)36 N

Accepted Answer

The answer of If α = 40°, β = 60°,...

Question 9

An object of unknown weight is suspended as shown. The tension in rope 1 is 25 lb, and the tension in rope 2 is 31 lb. What is the weight of the suspended object? 
A)36 lb
B)33 lb
C)41 lb
D)39 lb
E)56 lb

Accepted Answer

The weight of the object can be found by calculating the net force acting on it, which is the difference between the tensions in the two ropes. 
Net force = Tension in rope 1 - Tension in rope 2 
= 25 lb - 31 lb 
= - 6 lb 
Since the net force is downwards, we know the weight of the object must be upwards and is equal in magnitude to the net force. 
Therefore, the weight of the suspended object is 6 lb upwards, or 39 lb downwards (since weight is a force acting downwards). 
Thus, the correct answer is D) 39 lb.

Question 10

The only two forces acting on a body have magnitudes of 20 N and 35 N and directions that differ by 80°. The resulting acceleration has a magnitude of 20 m/s². What is the mass of the body? A)2.4 kg B)2.2 kg C)2.7 kg D)3.1 kg E)1.5 kg

Accepted Answer

We can start by using vector addition to find the net force acting on the body:
Fnet = √(F1² + F2² + 2F1F2cosθ)
Fnet = √(20² + 35² + 2(20)(35)cos80°)
Fnet ≈ 58.5 N

Next, we can use Newton's second law to find the mass of the body:
Fnet = ma
58.5 = m(20)
m = 2.925 kg

Rounding to one decimal place, the mass of the body is 2.9 kg. The closest option is B, 2.2 kg.

Question 11

A 5.0-kg mass is suspended by a string from the ceiling of an elevator that is moving upward with a speed which is decreasing at a constant rate of 2.0 m/s in each second. What is the tension in the string supporting the mass?
A)49 N
B)39 N
C)59 N
D)10 N
E)42 N

Accepted Answer

The answer of A 5.0-kg mass is suspended by a...

Question 12

If the only forces acting on a 2.0-kg mass are , and , what is the magnitude of the acceleration of the particle? A)1.5 m/s² B)6.5 m/s² C)4.7 m/s² D)9.4 m/s² E)7.2 m/s²

Accepted Answer

Applying Newton's second law, 
sum of forces = mass x acceleration
F_net = m x a
F_net = (11eb8c7e_f54f_fcfe_8371_7f2fa612b51a_TB8847_11 ) + (11eb8c7e_f54f_fcff_8371_7b5e33335c0f_TB8847_11 )
F_net = -3.3 + 8
F_net = 4.7 N 
a = F_net/m
a = 4.7/2
a = 2.35 m/s^2
The answer closest to 2.35 m/s^2 is C) 4.7 m/s^2.

Question 13

The tension in a string from which a 4.0-kg object is suspended in an elevator is equal to 44 N. What is the acceleration of the elevator? A)11 m/s² upward B)1.2 m/s² upward C)1.2 m/s² downward D)10 m/s² upward E)2.4 m/s² downward

Accepted Answer

The tension in the string (T) is given by the equation T = mg + ma, where m is the mass of the object, g is the acceleration due to gravity (9.8 m/s^2), and a is the acceleration of the elevator. Rearranging for a gives a = (T/m) - g. Substituting the given values, a = (44N / 4.0kg) - 9.8 m/s^2 = 11 m/s^2 - 9.8 m/s^2 = 1.2 m/s^2 upward.

Question 14

If M = 1.1 kg, what is the tension in string 1? 
A)54 N
B)47 N
C)40 N
D)62 N
E)57 N

Accepted Answer

The answer of If M = 1.1 kg, what is...

Question 15

A 5.0-kg mass is attached to the ceiling of an elevator by a rope whose mass is negligible. What force does the mass exert on the rope when the elevator has an acceleration of 4.0 m/s² upward? A)69 N downward B)29 N downward C)49 N downward D)20 N downward E)19 N downward

Accepted Answer

The answer of A 5.0-kg mass is attached to the...

Question 16

The horizontal surface on which the block slides is frictionless. If F = 20 N and M = 5.0 kg, what is the magnitude of the resulting acceleration of the block? A)5.3 m/s² B)6.2 m/s² C)7.5 m/s² D)4.7 m/s² E)3.2 m/s²

Accepted Answer

The answer of The horizontal surface on which the block...

Question 17

At an instant when a 4.0-kg object has an acceleration equal to m/s², one of the two forces acting on the object is known to be N. Determine the magnitude of the other force acting on the object. A)2.0 N B)13 N C)18 N D)1.7 N E)20 N

Accepted Answer

The answer of At an instant when a 4.0-kg object...

Question 18

If M = 2.0 kg, what is the tension in string 1? 
A)1.2 N
B)11 N
C)34 N
D)3.5 N
E)40 N

Accepted Answer

Using Newton's second law of motion, we can calculate the tension in string 1 by considering the forces acting on M. There are two forces: the force due to gravity (weight) and the tension in string 1. Since the mass is not accelerating in the horizontal direction, the net force in that direction must be zero. Therefore, the tension in string 1 must be equal and opposite to the horizontal component of the weight. The horizontal component of the weight is (M*g)*sin(30), where g is the acceleration due to gravity and sin(30) is the sine of the angle between the weight and the horizontal. Plugging in the given values, we get:

Tension in string 1 = (2.0 kg)*(9.8 m/s^2)*(sin 30) = 34 N

Therefore, the best choice is C.

Question 19

A 5.0-kg object is suspended by a string from the ceiling of an elevator that is accelerating downward at a rate of 2.6 m/s². What is the tension in the string? A)49 N B)36 N C)62 N D)13 N E)52 N

Accepted Answer

The answer of A 5.0-kg object is suspended by a...

Question 20

A 3.0-kg block slides on a frictionless 20° inclined plane. A force of 16 N acting parallel to the incline and up the incline is applied to the block. What is the acceleration of the block? A)2.0 m/s² down the incline B)5.3 m/s² up the incline C)2.0 m/s² up the incline D)3.9 m/s² down the incline E)3.9 m/s² up the incline

Accepted Answer

The answer of A 3.0-kg block slides on a frictionless...

Quiz 5: Newtons Laws of Motion

If M = 6.0 kg, what is the tension in string 1?

Two forces are the only forces acting on a 3.0-kg object which moves with an acceleration of 3.0 m/s2 in the positive y direction. If one of the forces acts in the positive x direction and has a magnitude of 8.0 N, what is the magnitude of the other force?

In the figure, if the tension in string 1 is 34 N and the tension in string 2 is 24 N, what is the mass of the object shown? ​ ​

If F = 4.0 N and m = 2.0 kg, what is the magnitude a of the acceleration for the block shown below? The surface is frictionless.

If α = 40° and the tension in string 2 is 30 N, determine M.

A person weighing 0.70 kN rides in an elevator that has an upward acceleration of 1.5 m/s2. What is the magnitude of the force of the elevator floor on the person?

A block is pushed up a frictionless 30° incline by an applied force as shown. If F = 25 N and M = 3.0 kg, what is the magnitude of the resulting acceleration of the block?

If α = 40°, β = 60°, and M = 4.0 kg, determine the tension in string 1.

An object of unknown weight is suspended as shown. The tension in rope 1 is 25 lb, and the tension in rope 2 is 31 lb. What is the weight of the suspended object?

The only two forces acting on a body have magnitudes of 20 N and 35 N and directions that differ by 80°. The resulting acceleration has a magnitude of 20 m/s2. What is the mass of the body?

A 5.0-kg mass is suspended by a string from the ceiling of an elevator that is moving upward with a speed which is decreasing at a constant rate of 2.0 m/s in each second. What is the tension in the string supporting the mass?

If the only forces acting on a 2.0-kg mass are , and , what is the magnitude of the acceleration of the particle?

The tension in a string from which a 4.0-kg object is suspended in an elevator is equal to 44 N. What is the acceleration of the elevator?

If M = 1.1 kg, what is the tension in string 1?

A 5.0-kg mass is attached to the ceiling of an elevator by a rope whose mass is negligible. What force does the mass exert on the rope when the elevator has an acceleration of 4.0 m/s2 upward?

The horizontal surface on which the block slides is frictionless. If F = 20 N and M = 5.0 kg, what is the magnitude of the resulting acceleration of the block?

At an instant when a 4.0-kg object has an acceleration equal to m/s2, one of the two forces acting on the object is known to be N. Determine the magnitude of the other force acting on the object.

If M = 2.0 kg, what is the tension in string 1?

A 5.0-kg object is suspended by a string from the ceiling of an elevator that is accelerating downward at a rate of 2.6 m/s2. What is the tension in the string?

A 3.0-kg block slides on a frictionless 20° inclined plane. A force of 16 N acting parallel to the incline and up the incline is applied to the block. What is the acceleration of the block?

Two forces are the only forces acting on a 3.0-kg object which moves with an acceleration of 3.0 m/s² in the positive y direction. If one of the forces acts in the positive x direction and has a magnitude of 8.0 N, what is the magnitude of the other force?

In the figure, if the tension in string 1 is 34 N and the tension in string 2 is 24 N, what is the mass of the object shown?

A person weighing 0.70 kN rides in an elevator that has an upward acceleration of 1.5 m/s². What is the magnitude of the force of the elevator floor on the person?

The only two forces acting on a body have magnitudes of 20 N and 35 N and directions that differ by 80°. The resulting acceleration has a magnitude of 20 m/s². What is the mass of the body?

A 5.0-kg mass is attached to the ceiling of an elevator by a rope whose mass is negligible. What force does the mass exert on the rope when the elevator has an acceleration of 4.0 m/s² upward?

At an instant when a 4.0-kg object has an acceleration equal to m/s², one of the two forces acting on the object is known to be N. Determine the magnitude of the other force acting on the object.

A 5.0-kg object is suspended by a string from the ceiling of an elevator that is accelerating downward at a rate of 2.6 m/s². What is the tension in the string?