Chapter 13 - Work & Machines

Work is not

• a scalar quantity.

• dependent on the distance that an object moves.

• a force over a period of time.

• related to energy.

Tags

NGSS.MS-PS3-5

What is the SI unit of work?

• horsepower

• joule

• newton

• watt

Tags

NGSS.HS-PS2-1

Work done on an object depends on

• any force applied to the object.

• the force parallel to the object's movement.

• the force perpendicular to the object's movement.

• the amount of time that the force is applied.

A driver pushes on a car with a force of 8000 N for 15 s but is unable to move it. How much work is done?

• 0 J

• 600 J

• 8000 J

• 120 000 J

Driving a car 100 m requires the same amount of __________ as pushing it 100 m by hand.

• power

• power and energy

• time

• work

Tags

NGSS.MS-PS3-5

We use simple machines in order to

• increase energy output.

• decrease the amount of work.

• make work easier to do.

• all the other answers.

A machine with a mechanical advantage of greater than 1 will multiply __________.

• distance

• force

• work

• all the other answers

What is the name for the turning force of a lever?

• fulcrum

• horsepower

• newton

• torque

A seesaw is __________.

• a first-class lever

• a second-class lever

• a third-class lever

• not a lever

Which of the following is a second-class lever?

• a crowbar

• pliers

• salad tongs

• a wheelbarrow