Forces

Two forces act on a block as shown in the picture.

What is the net force on the block?

• 10 N to the right

• 10 N to the left

• 30 N to the right

• 30 N to the left

A rock on Earth has a mass of 750 kg and a weight of 7,350 N. If the rock is taken into outer space, how will its mass and weight be affected?

• The weight and mass will remain the same because they are not altered by the effects of gravity.

• The weight will remain the same, but the mass will change because of the effects of gravity.

• The mass will be 76.5 kg, and the weight will increase because of the effects of gravity.

• The mass will be 750 kg, but the weight will decrease because of the effects of gravity.

There is a very slight change in gravity at the top of a mountain. Which property would MOST likely be less at the top of a mountain?

• mass

• weight

• body density

• body temperature

What causes a free falling object to accelerate?

• gravity

• inertia

• initial speed

• initial direction

A student stands on a scale, and the scale reads 85 pounds. What is being measured by the scale?

• the force of gravity acting on the student

• the air pressure surrounding the student

• the mass of the student

• the volume of the student

Which sentence correctly describes a friction force?

• It acts in the same direction as the motion of an object.

• It acts in a direction opposite to the motion of an object.

• It acts in a direction perpendicular to the motion of an object.

• It acts in the same direction as the force of gravity on an object.

As the wheels of a train move along the train tracks, what type of friction exists between the wheels and the tracks?

• fluid friction

• static friction

• rolling friction

• sliding friction

The action of swimmers using their arms to propel themselves through the water is an example of what law?

• Newton’s first law of motion

• Newton’s third law of motion

• law of conservation of linear momentum

• law of conservation of angular momentum

Which of these causes matter to resist a change in motion?

• inertia

• gravity

• friction

• weight

During a magic show, a magician quickly pulls a tablecloth off of a table set with dishes without disturbing the dishes. What law explains why the dishes did not move when the tablecloth was pulled out from under them?

• Newton’s universal law of gravitation

• Newton’s first law of motion

• Newton’s second law of motion

• Newton’s third law of motion