Question

Answer Check Please?

1. Which of these is not a conservative force and does not have a form of potential energy connected with it?
(Points : 1)
gravity

electric attraction and repulsion

friction

magnetic attraction and repulsion


Question 2. 2. Which of these is true about kinetic energy but not necessarily true about potential energy?
(Points : 1)
The kinetic energy of an object is never negative.

Kinetic energy depends on position.

Kinetic energy increases with height.

Kinetic energy is a scalar.

Answer 1

3. In which situation does the energy constantly change from gravitational potential energy to kinetic energy?
(Points : 1)
A ball is dropped off a cliff into a canyon.

A ball rests on a table.

A meteor flies through space.

A ball is thrown upward into the air and reaches its highest point.


Question 4. 4. A 22 kg sled is pushed for 5.2 m with a horizontal force of 20 N, starting from rest. Ignore friction. Find the final speed of the sled.
(Points : 1)
2.2 m/s

3.1 m/s

4.7 m/s

9.5 m/s


Question 5. 5. A 1,200 kg car rolls down a hill with its brakes off and transmission in neutral. At one moment it is moving 5.0 m/s. A little later it is moving at 8.2 m/s. How much did its height change between the two times? Assume friction and air resistance have no effect on its motion.
(Points : 1)
1.5 m

2.2 m

4.3 m

1.9 m


Question 6. 6. An 80.0 kg hiker walks a distance of 400.0 m along a road that slopes 5.0 degrees upward and then stops. What is the hiker's final gravitational potential energy relative to her original position? You may use a trigonometry table.
(Points : 1)
784 J

3.9 × 103 J

2.7 × 104 J

3.1 × 105 J


Question 7. 7. An 80.0 kg skier slides down a hill shaped as shown. Assume the skier begins to slide down the hill without friction or air resistance and is accelerated only by the effect of gravity. The skier is moving at 15 m/s at the bottom of the slope. At what height above this did the skier start?

(Points : 1)
1.2 m

11 m

23 m

288 m

Answer 2

Answers:

1.) A-Gravity
2.) B- Kinetic Energy depends on position
3.) A- A ball is dropped off in the Grand Canyon
4.) B- 3.1 m/s
5.) B- 2.2 m
6.) C-2.7*10^4 J
7.) C- 23

Answer 3

@Isaiah.Feynman