Unit 7 Review

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.

If the mass of an object on Earth is 18 grams, what would the mass of the same object be on the Moon?

• 0 grams

• 3 grams

• 9 grams

• 18 grams

What unit do scientists use to measure force?

• Newtons

• Grams

• Meters

• Meters per second

In tug of war, one student is pulling with a force of 20 N east. The other student pulls with a force of 20 N west. What is the net force?

• 40 N west

• 40 N east

• 0 N

• 10 N south

When a hammer strikes a nail, the nail

• exerts balanced forces that helps it from moving

• exerts a force equal to the weight of the hammer

• exerts an unbalanced force that changes its velocity

• exerts an equal and opposite force back on the hammer

Which object will have the greatest acceleration if acted upon by a net force of 100 N?

• 5-kg object

• 25-kg object

• 50-kg object

• 100-kg object

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

• Newton's first law

• Newton's third law

• Law of conservation of linear momentum

• Law of conservation of angular momentum

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

A spring balance determines that an unknown mass has a weight of 24.5 N. Find the mass.

• 2.5 kg

• 25 kg

• 0.25 kg

• 0.4 kg

Which statement is true about an object in freefall? Assume negligible air resistance.

• The object has a constant velocity

• The object has a constant acceleration

• The acceleration of the object increases as it falls

• The velocity decreases as the acceleration decreases as it falls