Physics - Ch. 8

Things to Know

100

What do we find in the area underneath a force-position graph?

Work

200

What is the difference between kinetic and potential energy?

Kinetic energy - the energy of a moving object

Potential energy - the energy of an object based on its position

300

What does Hooke's Law state?

Hooke’s law - any force used to stretch or compress the spring will be in the same direction as its displacement

400

When is total mechanical energy conserved during a process?

When only conservative forces are used

500

What is work?

the product of the force component that is parallel to an object’s motion and the displacement of the object

Solving

100

A 4.54 * 10³ N of force 15.4 s to lift a concrete pillar 25.0 m.   How much power does it produce?

7.42 * 10³ W

200

A 1.2 kg rock is moved 39.1 m upward in 16 seconds.  What is the work done on the rock?

4.6 * 10⁴ J

300

Mr. Osinga weighs 81.6 kg.  He is launched from the surface of Earth (R_V = 6.38 *10⁶ m, M = 5.97*10²⁴ kg).  What is the escape velocity needed to get him out of earth?

1.12 * 10⁴ m/s

400

A 93.64 kg mass is pushed 1.0 m into a spring (the mass and spring are attached).  The spring constant is 3 N/m. After being let go, the mass flies in the opposite direction.  

What is the speed of the mass as it is 1.5 m away from the equilibrium position?

.127 m/s

500

A 9.31 * 10⁶ kg minivan is travelling at 40.1 m/s.

What is the power delivered by the engine?

What is the kinetic energy of the car?

3.67 * 10⁹ W

2.89 * 10³ J