Physical Science Review

If a 300-N action force is exerted to the right, the reaction force will be ____.

• 300 N to the left

• 600 N to the left

• 300 N to the right

Sally and Jim do the same amount of work. Sally does the work in 2.3 hours and Jim does it in 2.5 hours. Who is more powerful?

• Sally used more power because she did the work faster.

• Jim used more power because he did more work.

• Jim used more power because he did the work faster.

For any object, the greater the force that's applied to it, the greater its ____ will be.

• inertia

• acceleration

• mass

While walking on the moon an astronaut dropped a hammer and a feather from the same height. Because the moon has no atmosphere (no air), the hammer and feather that are dropped from the same height at the same time will ____.

• fall at the same rate

• float

• fall at different rates

Which of the following would most greatly affect the friction between two surfaces?

• the speed

• the texture of the surface on each object

• the density

On Earth, the ocean tides are caused by the gravitational pull of the Sun and Moon. The Moon’s effect on the tides is greater than the Sun’s because ____.

• the Moon is much closer to Earth than the Sun

• the Sun is almost the same size as the Moon

• the Sun has a greater mass than the Moon

Calculate the force needed to push a piano with a mass of 240 kg and an acceleration of 2 m/s².

• 480 N

• 120 J

• 480 J

Marisa and Norma were testing Newton’s Second Law to show that Force = mass x acceleration and were unsure about which way to set up the investigation. Whichequipment would be best to use?

• a scale, a metric ruler, a steel ball, and a stop watch

• a car on a track and a stopwatch

• a graduated cylinder, water, a bolt, and a balance

On Earth, a feather will fall through the air more slowly than a brick because of ____.

• air resistance

• inertia

• gravity

The size of the gravitational force between two objects depends on their ____.

• frictional forces

• speed and direction

• masses and the distance between them