Physics
posted by rachel .
A child's game consists of a block that
attaches to a table with a suction cup, a
spring connected to that block, a ball, and a
launching ramp. By compressing the
spring, the child can launch the ball up the
ramp. The spring has a spring constant k,
the ball has a mass m, and the ramp raises a
height h. The spring is compressed a
distance S in order to launch the ball. When
the ball leaves the launching ramp its
velocity makes an angle Î¸ with respect to the horizontal.
(a) Calculate the velocity of the ball when it just leaves the launching ramp (both magnitude and
direction. Be sure to specify your coordinate system.)
(b) The spring constant = 1000.0 N/m, the spring's compression is 4.00 cm, the ball's mass is
55.0 grams, the height of the ramp is 15.0 cm, and the top of the table is 1.20 m above the floor.
With what total speed will the ball hit the floor? (Use g = 10.0 m/s2)

I assume you have to ignore friction, and assume the ball does not start to roll going up the ramp. Doing that, use energy considerations.
SpringcompressedEnergy + initialPE
=KE final
The initial PE is mg*1.35
solve for the total KE when it hits the floor, and from that, its speed.
I will be happy to check your work. 
how come for part a. when i solve for Vf (which becomes V0 of the projectile motion), i get a negative value.. since i got this equation...
1/2ks^2+mgh+1/2mv^2 = 0
solving for v.. i get
v = sqrt((2ghks^2/m)
thats what is confusing me. so im not shure if i did it correctly. 
SpringcompressedEnergy + initialPE
=KE final
1/2 k s^2+mgh=1/2 m v^2 This v is the velocity at the floor when it hits. h is the intial height of the ball (table). h is 1.20, not 1.35 as I indicated.
v=sqrt(2gh+ks^2/m)
The above is just sayingthe intial energy has to equal the final energy, and initial energy is spring energy + initial potential energy (mg*1.2) 
this doesnt work
Respond to this Question
Similar Questions

Physics
A child's toy consists of a block that attaches to a table with a suction cup, a spring connected to that block, a ball, and a launching ramp. (Intro 1 figure) The spring has a spring constant k, the ball has a mass m, and the ramp … 
physics
You push a 2.0 kg block against a horizontal spring, compressing the spring by 15 cm. Then you release the block, and the spring sends it sliding across a tabletop. It stops 75 cm from where you released it. The spring constant is … 
physics
You push a 1.9 kg block against a horizontal spring, compressing the spring by 13 cm. Then you release the block, and the spring sends it sliding across a tabletop. It stops 60 cm from where you released it. The spring constant is … 
physics
You push a 4.6 kg block against a horizontal spring, compressing the spring by 27 cm. Then you release the block, and the spring sends it sliding across a tabletop. It stops 63 cm from where you released it. The spring constant is … 
Physics
You push a 2.5 kg block against a horizontal spring, compressing the spring by 16 cm. Then you release the block, and the spring sends it sliding across a tabletop. It stops 60 cm from where you released it. The spring constant is … 
physics
The spring in the muzzle of a child's spring gun has a spring constant of 780 N/m. To shoot a ball from the gun, first the spring is compressed and then the ball is placed on it. The gun's trigger then releases the spring, which pushes … 
physics
You push a 1.3 kg block against a horizontal spring, compressing the spring by 22 cm. Then you release the block, and the spring sends it sliding across a tabletop. It stops 79 cm from where you released it. The spring constant is … 
Physics
A 540 g block is released from rest at height h0 above a vertical spring with spring constant k = 320 N/m and negligible mass. The block sticks to the spring and momentarily stops after compressing the spring 19.8 cm. How much work … 
Physics
A 540 g block is released from rest at height h0 above a vertical spring with spring constant k = 320 N/m and negligible mass. The block sticks to the spring and momentarily stops after compressing the spring 19.8 cm. How much work … 
Physics please help?????
A 540 g block is released from rest at height h0 above a vertical spring with spring constant k = 320 N/m and negligible mass. The block sticks to the spring and momentarily stops after compressing the spring 19.8 cm. How much work …