What would be the reaction to hand's force on the box?

- 13 N
- 14 N
- 0 N
- 28 N

Explanation: the reaction to hand's force on the box is equal to your hand's force.

Question 2: Assume that the surface gravity of Mars is 4 m/s

80 kg were parachuting on this planet.

Calculate the force exerted by air resistance at terminal velocity (i.e., gravity or weight is equal to the opposite force of air resistance).

- 3200 N
- 320 N
- 0 N
- 160 N

Explanation: force magnitude = surface gravity of Mars × mass of the astronaut = 4 m/s

Question 3: The net force acting on a body gives the direction of the ________ of the body.

- speed
- velocity
- acceleration
- posture

Question 4: Assume a body of mass 1 kg is pushed across a horizontal table by a force of 1 N and the acceleration was measured at 0.8 m/s

Calculate the force of friction.

- 0 N
- 2 N
- 0.5 N
- 0.2 N

Exlanation: F

Hence the friction = F

Question 5: A block of mass 5 kg is acted upon by a single force, generating an acceleration of 3.0 /s

The value of the force is

- 10 N
- 20 N
- 15 N
- 12 N

Exlanation: F

Question 6: A block of mass 20 kg on horizontal surface without friction is acted upon by two forces:

a horizontal force of 90 N acting to the right and a horizontal force of 50 N to the left.

Find the acceleration of the block and its direction.

- 1 m/s
^{2} - 2 m/s
^{2} - 5 m/s
^{2} - 4 m/s
^{2}

Explanation: F

Question 7: Assume a crate is acted upon by a net force of 200 N and an acceleration is measured at 5.0 m/s

Calculate the weight of the crate.

- 388 N
- 290 N
- 400 N
- 392 N

Explanation: F = mass (m) × acceleration (a), which implies that m = 200 N / 5 m/s

Weight = mass × 9.8 m/s

Question 8: A block of mass 100 kg that is free to roll on a level surface is acted upon a net horizontal force of 400 N.

The acceleration is

- 1 m/s
^{2} - 2 m/s
^{2} - 3 m/s
^{2} - 4 m/s
^{2}

Explanation: F = mass (m) × acceleration (a), and so a = 400 N / 100 kg = 4 m/s

Question 9: The frictional force, due to air resistance, acting on an object is always

- in the opposite direction to the object's friction.
- in the opposite direction to the object's motion.
- in the opposite direction to the object's mass.
- in the opposite direction to the object's vertical force.

Question 10: Two blocks B

What is the relationship between the two accelerations?

- Acceleration of B2 is larger
- Acceleration of B1 is larger.
- equal.
- no relationship

Explanation: F

Using using mathematical substitution, we obtain from the first equation m = 50 / (a

So, 50 × a

Question 11: Assume your weight is 700 newtons and you picked up a box from the ground with a force of 100 newtons.

Find the force the box exerts on you.

- 100 N
- 700 N
- 350 N
- 0 N

Explanation: The force the box exerts on you is equal to the force used to picked up the box from the ground.

Question 12: Assume a force is exerted on person P

The same force is being used on 60-kg person

- a smaller acceleration.
- a larger acceleration.
- same acceleration.
- zero acceleration.

Explanation: The force exerted on P

Hence, mass of P

which means, 70 kg × 2.0 m/s

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Date of last modification: Summer , 2019