Download Name: Date: Pd: ______ Honors Physics Mr. Roberts Spring Energy

Name: __________________________________________ Date: _________________________ Pd: __________
Honors Physics
Mr. Roberts
Spring Energy & Conservation of Energy with Friction Problem Set
1. You want to store 1,000 J of energy in an ideal spring when it is compressed by only 2.5 cm. What should be
the force constant of the spring?
2. An ideal spring has a spring constant of 60 N/m. How much energy does it store when it is stretched by 1
centimeter?
3. Assuming negligible friction, what spring constant would be needed by the spring in a “B-B gun” to fire a 10
g pellet to a height of 100 m if the spring is initially compressed by 0.10 m?
4. A 1500 kg car moving at 25 m/s hits an initially uncompressed horizontal ideal spring with a spring constant
of 2.0x106 N/m. What is the maximum distance the spring compresses?
5. A 1500 kg car accelerates from rest to 25 m/s in 7.0 s. What is the average power delivered by the engine?
6. A 7.5 kg otter slides down a hill, starting from rest at the top. The sloped surface of the hill is 8.8 m long,
and the otter starts 6.5 m above the base. If the speed of the otter at the bottom of the hill is 9.2 m/s, how
much energy was lost due to friction?
7. A 60 kg skier starts from rest from the top of a 50 m high slope. If the work done by friction is -6000 J, what
is the speed of the skier on reaching the bottom of the slope?
8. A 10 kg object is initially at rest at the top of a frictionless inclined plane that rises 30° above the horizontal.
At the top, the object is initially 8.0 m from the bottom of the incline, as shown in the figure. When the
object is released from this position, it eventually stops at a distance d from the bottom of the inclined plane
along a horizontal surface. The coefficient of kinetic friction between the horizontal surface and the object
is 0.20. Find the distance d.
Problems 9 & 10 pertain to the figure shown
to the right.
9. A 0.12-kg block is held in place against the
spring by a 35-N horizontal external force. The external force is removed, and the block is projected with a
velocity v1 = 1.2 m/s when it separates from the spring, as shown in the figure. The block descends a ramp
and has a velocity v2 = 1.4 m/s at the bottom of the ramp. The track is frictionless between points A and B.
The block enters a rough section at B, extending to E. The coefficient of kinetic friction between the block and
the rough surface is 0.26. The block moves on to D, where it stops. By how many centimeters was the spring
initially compressed?
10. As shown in the figure, a 1.45-kg block is held in place against the spring by a 21-N horizontal external force.
The external force is removed, and the block is projected with a velocity v1 = 1.2 m/s as it separates from the
spring. The block descends a ramp and has a velocity v2 = 2.1 m/s at the bottom. The track is frictionless
between points A and B. The block enters a rough section at B, extending to E. The coefficient of kinetic
friction between the block and the rough surface is 0.29. The velocity of the block is v3 = 1.4 m/s at C. The
block moves on to D, where it stops. How much work is done by friction between points B and C?
11. A sled is moving along a horizontal surface with a speed of 5.7 m/s. It then slides up a rough hill having a slope
of 11° above the horizontal. The coefficient of kinetic friction between the sled and the surface of the hill is
0.26. How far along the surface does the block travel up the incline?