NAT REVIEW

Which of the following is always true about net force?

• It causes motion

• It makes the objects speed up

• Its SI unit is newton

• It is inversely proportional to acceleration

1. You are standing on a scale in an elevator. You notice that your weight is decreasing.

What can you conclude? The elevator is_ .

• Accelerating upward

• Moving at constant acceleration upward

• Accelerating downward

• Moving at constant acceleration downward

The acceleration due to gravity of Earth is _____________

• 9.80 m²/s, downward

• 9.80 m/s, downward

• 9.80 km²/s, downward

• 9.80 m/s², downward

If your mass on Earth is 55kg, what is your mass on the moon?

• 55 kg

• 550 kg

• 55 N

• 550 N

The seatbelt of your car protects you from your ______

• acceleration

• Inertia

• Mass

• Velocity

Which of the following is not consistent with a car which is accelerating?

• Moving with an increasing speed

• Moving with a high speed

• Moving with a decreasing speed.

• Changing direction

If the force of gravity on balloon is 3,000N, and the lift force provided by the atmosphere is 2,900N, in which direction is the net force acting?

• Upward

• Towards the East

• Downward

• There is no net force

If a horse pulls on a calesa at rest, the calesa pulls back equally as much on the horse. Will the calesa be set into motion?

• No, because the forces cancel each other.

• Yes, because there is a time delay between action and reaction.

• Yes, because there is a net force acting on the calesa.

• Yes, because the horse’s pull on the calesa is larger than the calesa’s pull on the horse.

Inertia is the property of mass in which an object at rest wants to stay at rest, and an object that is moving in a straight line wants to _____.

• Also stay at rest.

• Stay moving in a circular motion unless acted upon by another force.

• Stay moving in a straight line unless acted upon by another force.

• Stay moving in a straight line, but only if it has been acted upon by another force.

Which of the following the sum of all the forces acting on an object?

• contact force

• non-contact force

• balanced force

• net force