Question 1

You swing a bat and hit a heavy box with a force of 1500 N. According to Newton's third law, what is the force the box exerts on the bat?

Accepted Answer

Exactly 1500 N whether or not the box moves.

Question 2

A stalled car is being pushed up a hill at constant velocity by three people. What is the net force on the car?

Accepted Answer

Zero.

Question 3

A 20-ton truck collides with a 1500-lb car and causes a lot of damage to the car. During the collision, which statement is correct?

Accepted Answer

The force on the truck due to the collision is exactly equal to the force on the car.

Question 4

Refer to the first image. Two objects, each of weight $$W$$, hang vertically by spring scales as shown. The pulleys and strings have negligible weight and friction. What is the reading in each scale?

Accepted Answer

$$W$$

Question 5

Refer to the second image. A fish weighing 16 N is weighed using two spring scales, each of negligible weight, as shown. What will be the readings of the scales?

Accepted Answer

Each scale will read 16 N.

Question 6

An object is moving forward with a constant velocity. Which statement about this object MUST be true?

Accepted Answer

The net force on the object is zero.

Question 7

A ball is tossed vertically upward. When it reaches its highest point (before falling back downward), which of the following is true?

Accepted Answer

The velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward.

Question 8

Refer to the third image. Two weights are connected by a massless wire and pulled upward with a constant speed of 1.50 m/s by a vertical pull $$P. $$The tension in the wire is $$T. $$Which one of the following relationships between $$T$$ and $$P$$ must be true?

Accepted Answer

$$P = T + 25\ \mathrm{N}$$

Question 9

A block lies on a horizontal frictionless surface. A horizontal force of 100 N is applied to the block, giving rise to an acceleration of $$3.0\ \mathrm{m/s^2$}. $$What is the mass of the block?

Accepted Answer

$$33.3\ \mathrm{kg}$$

Question 10

If a $$5.0\ \mathrm{kg}$$ box is pulled simultaneously by a $$10.0\ \mathrm{N}$$ force and a $$5.0\ \mathrm{N}$$ force in the same direction, what is its acceleration?

Accepted Answer

$$3.0\ \mathrm{m/s^2$}$$

Question 11

A $$7.0\ \mathrm{kg}$$ object is acted on by two forces. One of the forces is $$10.0\ \mathrm{N}$$ acting toward the east. If the acceleration of the object is $$1.0\ \mathrm{m/s^2$}$$ toward the east, what is the other force?

Accepted Answer

$$3.0\ \mathrm{N}$$ west

Question 12

A $$4.00\ \mathrm{kg}$$ object is acted on by four forces: $$F_1 = 300$$\ \mathrm{N}$$ east, F_2$ = 700\ \mathrm{N}$$ north, $$F_3 = 500$$\ \mathrm{N}$$ west, F_4$ = 600\ \mathrm{N}$$ south. What is the magnitude and direction of the net force?

Accepted Answer

$$224\ \mathrm{N} in a $$direction $$63.4^\circ$$ north of west

Question 13

A $$50.0\ \mathrm{N}$$ box is sliding on a rough horizontal floor. The only horizontal force acting on it is friction. If the box is sliding to the right at $$1.75\ \mathrm{m/s}$$ and stops in $$2.25\ \mathrm{s}$$ with uniform acceleration, what magnitude force does friction exert on this box?

Accepted Answer

$$3.97\ \mathrm{N}$$

Question 14

A block is on a frictionless horizontal table on Earth. This block accelerates at $$1.9\ \mathrm{m/s^2$}$$ when a horizontal force is applied. The block and table are then set up on the Moon, where the acceleration due to gravity is $$1.62\ \mathrm{m/s^2$}. $$What is the weight of the block on the Moon?

Accepted Answer

$$77\ \mathrm{N}$$

Question 15

An $$1100\ \mathrm{kg}$$ car traveling at $$27.0\ \mathrm{m/s}$$ starts to slow down and comes to a complete stop in $$578\ \mathrm{m}. $$What is the magnitude of the average braking force acting on the car?

Accepted Answer

$$690\ \mathrm{N}$$

Question 16

A tow-truck has a maximum acceleration of $$3.0\ \mathrm{m/s^2$} on $$its own. What would be the maximum acceleration when this truck is towing a bus of twice its own mass?

Accepted Answer

$$1.0\ \mathrm{m/s^2$}$$

Question 17

A $$10,000\ \mathrm{kg}$$ rocket blasts off from Earth with a uniform upward acceleration of $$2.00\ \mathrm{m/s^2$}$$ and feels no air resistance. What is the upward thrust force its engines must provide?

Accepted Answer

$$118,000\ \mathrm{N}$$

Question 18

A $$60.0\ \mathrm{kg}$$ person rides in an elevator while standing on a scale. The scale reads $$400\ \mathrm{N}. $$What is the acceleration of the elevator?

Accepted Answer

$$6.67\ \mathrm{m/s^2$}$$ downward

Question 19

A $$60.0\ \mathrm{kg}$$ person rides in an elevator while standing on a scale. The elevator is traveling downward but slowing down at a rate of $$2.00\ \mathrm{m/s^2$}. $$What is the reading on the scale?

Accepted Answer

$$708\ \mathrm{N}$$

Newton's Laws and Forces: Practice Questions with Step-by-Step Guidance

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