Physical Science Ch. 13 Review

If a boy pushes on a parked vehicle with a force of 350 N and the car doesn't move, how much work was done?

• 350 N

• 350 J

• 175 N

• Zero

What is the SI unit for work?

• kg*m²/s²

• J

• N*m

• All of the above

What is the power of a weightlifter that presses a 500 N weight 2.5 m over his head in 5 seconds?

• 6250 N

• 250 W

• 250 N

• 6250 W

What is a machine?

• can multiply and change the direction of an input force

• decreases the amount of work done by a given force

• increases energy

• requires less work to do a given task

What is the mechanical advantage of a single, fixed pulley?

• 3

• 2

• 1

• 5

What does an inclined plane do?

• decreases the amount of work that is done

• changes the direction of the force only

• changes the magnitude of the force only

• changes both the magnitude and the direction of the force

What is an example of a compound machine?

• scissors

• lever

• pulley

• wedge

What is the gravitational potential energy of a 50 kg box that is 10.0 m above ground?

• 500 J

• 500 kg*m

• 4900 J

• 4900 kg*m

Which of the following is an example of mechanical energy?

• light energy

• potential energy

• chemical energy

• nuclear energy

What is the primary source of the sun's energy?

• potential energy

• nuclear fission

• chemical energy

• nuclear fusion