Download spring energy.notebook - Manhasset Public Schools

spring energy.notebook
February 07, 2017
11. Two boxes are connected to a frictionless pulley as shown. The system is released from rest. Using the principle of conservation of energy, determine the speed of the 15 kg box when it hits the ground. Feb 7­10:01 AM
500
W = Fd Force (N)
Energy stored in a spring is equal to the work done 400
to change the length of 300
the spring. 200
100
0
1
Find the work done by
stretching the spring 4 m?
2
x (m)
3
4
5
Mar 11­5:15 PM
1
February 07, 2017
Force
spring energy.notebook
x Area = 1/2 bh
= 1/2 Fx
= 1/2 kx x
= 1/2 kx2
= 1/2 kx2
PE spring Feb 23­8:20 PM
Feb 25­10:30 AM
2
spring energy.notebook
February 07, 2017
A spring‐loaded dart gun has a spring with a spring constant of 200 N/m. A 0.05 kg dart is placed in the gun by compressing the spring 8 cm. a. How much potential energy is stored in the spring?
b. How much kinetic energy will the dart get after it is released?
c. How fast will the dart be moving when it is released?
Feb 23­8:28 PM
2. A 4.5 kg crate moving at 2 m/s hits a spring and compresses the spring by 50
cm. Find the spring constant. Feb 22­9:13 AM
3
spring energy.notebook
February 07, 2017
3. A ball of mass, m, is released from a spring loaded gun and goes to a height, H. A ball of mass, 2m, is placed in the spring loaded gun. Determine how high the second ball will go.
Jan 31­9:39 AM
4. A rifle bullet of mass 10.0 grams strikes and becomes embedded in a wood block of mass 490 grams, which is at rest on a horizontal, frictionless surface. The block is attached to a spring bumper as shown. The impact compresses the spring, whose spring constant is 100 N/m, by 20 cm.
[a] What is the maximum potential energy of the spring?
[b] Determine the velocity with which the bullet and block first begin to move.
[c] What was the initial velocity of the bullet?
[d] What was the initial kinetic energy of the bullet?
[e] How much kinetic energy was "lost" in the collision? Where did it go?
Jan 30­11:08 AM
4
spring energy.notebook
February 07, 2017
5. Two blocks are placed on a frictionless ramp and held against a spring that is
compressed one­half meter. (The mass of the blocks and force constant of the
springs are also given for each system.) The blocks are then released from rest,
and the compressed spring causes the blocks to accelerate up the ramp while in
contact with the blocks. At the instant shown, the blocks are just about to lose
contact with the end of the spring.
Is the height that the block travels up the ramp in Case B, or the same in both cases?
Explain.
greater in Case A, greater
Feb 22­9:15 AM
5