Question 1

If object A has more mass than object B,
A) A will weigh more than B.
B) A will be harder to accelerate than B.
C) A will be harder to keep moving in a circle.
D) all of the above

Accepted Answer

All of the statements are correct. A heavier object due to more mass will weigh more, be harder to accelerate due to its inertia, and require more force to keep it moving in a circular path, according to Newton's laws of motion.

Question 2

You whirl a 2-kg body attached to a 1-meter cord around your head in a nearly horizontal circle with a speed of 4 m/s. The tension in the cord is
A) 2 N.
B) 4 N.
C) 8 N.
D) 16 N.
E) 32 N.

Accepted Answer

The answer of You whirl a 2-kg body attached to...

Question 3

Which is larger, a newton or a pound?
A) a newton
B) a pound
C) This question is nonsense-they don't measure the same physical quantity.
D) They are the same size.

Accepted Answer

The answer of Which is larger, a newton or a...

Question 4

The force needed to make an object move in a circle is
A) centripetal force.
B) weight.
C) kinetic friction.
D) static friction.
E) none of the above.

Accepted Answer

The force needed to make an object move in a circle is called the centripetal force, which acts towards the center of the circle and keeps the object moving in a circular path. Weight, kinetic friction, and static friction do not cause circular motion.

Question 5

A car moving at a constant speed goes around a curve of 400-ft radius and then goes around a second curve of 200-ft radius. The centripetal force acting on the car as it goes around the 200-ft radius curve is ___________ the value of the centripetal force acting on the car as it goes around the 400-ft radius curve.
A) one quarter
B) one half
C) the same as
D) twice
E) four times

Accepted Answer

The centripetal force is proportional to the square of the velocity and inversely proportional to the radius of the curve. Since the car is moving at a constant speed, the velocity is the same for both curves. However, the radius of the second curve is half that of the first curve, so the centripetal force required to stay on the curve is four times greater. Therefore, the centripetal force acting on the car as it goes around the 200-ft radius curve is twice the value of the centripetal force acting on the car as it goes around the 400-ft radius curve.

Question 6

The SI units of acceleration are A) mi/h. B) km/h. C) m/s. D) m/s ². E) none of the above

Accepted Answer

The correct SI unit for acceleration is meters per second squared (m/s^2), which is option D, albeit with a typo. Acceleration is defined as the rate of change of velocity per unit of time, and its SI unit is m/s^2, not m/s as stated in option C or any of the other non-standard units listed.

Question 7

You roll a ball off a table and at the same time drop a second ball straight down from the edge of table. The second ball reaches the ground ____________ the first ball reaches the ground.
A) before
B) at the same time that
C) after
D) before or after, depending on the masses,
E) cannot be determined

Accepted Answer

Both balls will reach the ground at the same time because they both experience the same acceleration due to gravity, regardless of their masses. This is known as the Principle of Equivalence.

Question 8

Two identical cars are traveling around the same curve on a highway. One of them is moving at 60 mph, and the other is moving at 30 mph. The centripetal force acting on the car moving at 60 mph is __________ the value of the centripetal force acting on the car moving at 30 mph.
A) one quarter
B) one half
C) the same as
D) twice
E) four times

Accepted Answer

The centripetal force required to keep an object moving in a circle is directly proportional to the square of the velocity of the object (F = mv^2/r). Therefore, if one car is moving at twice the speed of the other, the faster car experiences four times the centripetal force (60 mph is twice 30 mph, so (2)^2 = 4).

Question 9

The SI units of velocity are A) mi/h. B) km/h. C) m/s ². D) m/s. E) none of the above

Accepted Answer

SI units of velocity are in meters per second (m/s). Choices A and B are not SI units, and choice C is not a valid unit of measure.

Question 10

An example of an action at a distance force is
A) tension.
B) weight.
C) static friction.
D) kinetic friction.
E) none of the above

Accepted Answer

Weight is an example of an action at a distance force, as it is the force of gravity between two objects that are not in physical contact with each other. Tension is a contact force, as it is the force transmitted through a string or rope that is in physical contact with both objects. Static and kinetic friction are also contact forces, as they involve the surfaces of two objects being in physical contact and resisting relative motion.

Question 11

Two forces of 4 N and 12 N act on a body simultaneously. The net force on the body is
A) 4 N.
B) 12 N.
C) 16 N.
D) 8 N.
E) impossible to tell from the given information.

Accepted Answer

The answer of Two forces of 4 N and 12...

Question 12

A 160 lb person has a mass of 160/32 = 5 slugs. A 160-lb person steps into an elevator and stands on a bathroom scale. Determine the scale reading for the given scenarios. The elevator is accelerating upwards at 2 ft/s ². A) 150 lb B) 160 lb C) 170 lb D) none of the above

Accepted Answer

When the elevator accelerates upwards, the apparent weight of the person increases due to the additional force required to accelerate them upwards along with the elevator. The apparent weight can be calculated using the formula $w = m(g + a)$, where $w$ is the apparent weight, $m$ is the mass in slugs, $g$ is the acceleration due to gravity (32 ft/s$^2$), and $a$ is the acceleration of the elevator (2 ft/s$^2$ upwards in this case). Substituting the given values, $w = 5(32 + 2) = 5 \times 34 = 170$ lb.

Question 13

The acceleration of a body is
A) always in the same direction as its velocity.
B) always in the same direction as the net force on the body.
C) in the direction that the body is moving.
D) equal to the net force on the body.
E) none of the above.

Accepted Answer

Acceleration is always in the same direction as the net force acting on the body, as described by Newton's second law (F=ma). The direction of the velocity may or may not be the same as the direction of the acceleration, depending on the presence of other forces or friction. The direction that the body is moving is not necessarily the same as the direction of acceleration.

Question 14

Starting from rest, a 2-kg body acquires a speed of 8 m/s in 2 seconds. The net force acting on the body is
A) 2 N.
B) 4 N.
C) 8 N.
D) 16 N.
E) 6 N.

Accepted Answer

The answer of Starting from rest, a 2-kg body acquires...

Question 15

When a freely falling object reaches its terminal speed,
A) it is still accelerating.
B) its acceleration is zero.
C) it is decelerating.
D) its acceleration cannot be determined.

Accepted Answer

When an object reaches its terminal speed, the air resistance force on the object becomes equal in magnitude to the force of gravity pulling it down. At this point, the net force on the object is zero and it stops accelerating. Therefore, the acceleration of the object is zero.

Question 16

You push on a block on frictionless ice with a force of 8 N, causing it to accelerate at 2 m/s ². The mass of the block is A) 2 kg. B) 4 kg. C) 8 kg. D) 16 kg. E) 6 kg.

Accepted Answer

We can use the formula F = ma, where F is the force applied, m is the mass of the object, and a is the acceleration produced.

F = 8 N 
a = 2 m/s^2

Substituting in the values, we get:

8 N = m x 2 m/s^2

Solving for m, we get:

m = 4 kg

Therefore, the mass of the block is 4 kg, which is choice B.

Question 17

The frequency of a body oscillating from a spring on the Moon is___________ the frequency of the same body oscillating from the same spring on Earth.
A) the same as
B) larger than
C) smaller than
D) not related to
E) depending on the mass, smaller or larger than

Accepted Answer

The frequency of a body oscillating from a spring depends on the spring constant and the mass of the body, not on the gravitational field where the oscillation occurs. Therefore, the frequency remains the same whether the oscillation happens on the Moon or on Earth.

Question 18

A 160 lb person has a mass of 160/32 = 5 slugs. A 160-lb person steps into an elevator and stands on a bathroom scale.  Determine the scale reading for the given scenarios. The elevator accelerates upwards and is now moving at a constant speed.
A) 150 lb
B) 160 lb
C) 170 lb
D) none of the above

Accepted Answer

Since the elevator is moving at a constant speed, the scale reading will be the same as the person's weight when they are standing still (i.e. 160 lb). The scale measures the normal force exerted by the person on it, and this force does not change when the elevator is moving at a constant speed. The scale reading would only be different if the elevator was accelerating or decelerating.

Question 19

The force that keeps your feet from sliding as you walk is
A) centripetal force.
B) weight.
C) kinetic friction.
D) static friction.
E) none of the above.

Accepted Answer

The force that keeps your feet from sliding as you walk is static friction. It is the friction force between two objects that are not moving relative to each other. In this case, it is between the soles of your shoes and the ground.

Question 20

If the net force on an object is zero,
A) there must be no forces acting on the object.
B) the object must be at rest.
C) the object's acceleration must be zero.
D) there can be no friction acting on the object.

Accepted Answer

If the net force on an object is zero, it means that the forces acting on the object are balanced. This does not necessarily mean that there are no forces acting on the object, as there could be multiple forces canceling each other out. The object could be moving with a constant velocity or be at rest. However, if the object is accelerating, then the net force cannot be zero. Therefore, choice C (the object's acceleration must be zero) is the best choice.

Quiz 2: Newton S Laws

If object A has more mass than object B,

You whirl a 2-kg body attached to a 1-meter cord around your head in a nearly horizontal circle with a speed of 4 m/s. The tension in the cord is

Which is larger, a newton or a pound?

The force needed to make an object move in a circle is

The SI units of acceleration are

You roll a ball off a table and at the same time drop a second ball straight down from the edge of table. The second ball reaches the ground ____________ the first ball reaches the ground.

Two identical cars are traveling around the same curve on a highway. One of them is moving at 60 mph, and the other is moving at 30 mph. The centripetal force acting on the car moving at 60 mph is __________ the value of the centripetal force acting on the car moving at 30 mph.

The SI units of velocity are

An example of an action at a distance force is

Two forces of 4 N and 12 N act on a body simultaneously. The net force on the body is

A 160 lb person has a mass of 160/32 = 5 slugs. A 160-lb person steps into an elevator and stands on a bathroom scale. Determine the scale reading for the given scenarios. The elevator is accelerating upwards at 2 ft/s 2.

The acceleration of a body is

Starting from rest, a 2-kg body acquires a speed of 8 m/s in 2 seconds. The net force acting on the body is

When a freely falling object reaches its terminal speed,

You push on a block on frictionless ice with a force of 8 N, causing it to accelerate at 2 m/s 2. The mass of the block is

The frequency of a body oscillating from a spring on the Moon is___________ the frequency of the same body oscillating from the same spring on Earth.

A 160 lb person has a mass of 160/32 = 5 slugs. A 160-lb person steps into an elevator and stands on a bathroom scale. Determine the scale reading for the given scenarios. The elevator accelerates upwards and is now moving at a constant speed.

The force that keeps your feet from sliding as you walk is

If the net force on an object is zero,

A 160 lb person has a mass of 160/32 = 5 slugs. A 160-lb person steps into an elevator and stands on a bathroom scale. Determine the scale reading for the given scenarios. The elevator is accelerating upwards at 2 ft/s ².

You push on a block on frictionless ice with a force of 8 N, causing it to accelerate at 2 m/s ². The mass of the block is