In procedure 1: suppose a cart of mass m = 708 g is initial moving at speed v 0
ID: 2099554 • Letter: I
Question
In procedure 1: suppose a cart of mass m = 708 g is initial moving at speed v0 = 5.29 m/s. It strikes a spring attached to a fixed wall, comes to a stop, and bounces back at speed vf = 3.96 m/s. Assume the track is frictionless.
a) Find the magnitude of the impulse exerted by the spring on the cart.
N-s
b) Find the energy lost in this collision.
J
c) If the cart was in contact with the spring for 589 ms, find the average force exerted by the spring on the cart.
N
In procedure 4: suppose the cart has mass m = 807 g, and it strikes the clay at speed vo = 5.3 m/s and comes to a dead stop. Assume the track is frictionless, and the clay is crushed inward by 1.5 cm.
a) Find the magnitude of the impulse exerted by the clay on the cart.
N-s
b) Find the magnitude of the average force exerted by the clay on the cart.
HINT: Use kinematics, assuming the force is constant during the impulse!
N
c) Find the time it took for the cart to come to rest while in contact with the clay.
s
Explanation / Answer
3a) impulse = dp = .708*(5.29+3.96)=6.549
b) dE = 0.5*.708*(3.96^2-5.29^2)=-4.36 J
c) F = dp/dt = 6.549/.589=11.12 N
4 a) impulse = dp = .807 *(5.3-0)=4.28
b) v^2 = v0^2 + 2 a x
0 = 5.3^2 -2*a*1.5E-2
a=936.3
F = ma = .807*936.3=756 N
c) v = v0 + at
0 = 5.3-936.3*t
t=0.00566 s