A 9.5 kg fullback, running at 8.2m/s, collides in midair with a 128 kg defensive tackle moving in the opposite

Question

Hey guys! I need help with this physics problem. Hope you guys can help me!!! Thanks a lot. =)

A 9.5 kg fullback, running at 8.2m/s, collides in midair with a 128 kg defensive tackle moving in the opposite direction. Both players end up with zero speed.
a. What was the fullback's momentum before the collision?
b. What was the change in the fullback's momentum?
c. What was the change in ther tackle's momentum?
d. What was the tackle's original momentum?
e. How fast was the tackle moving originally?

Hope you guys can explain it to me once you get the answers. Thanks. I really need your help. =)

Answer 1

momentum = mass * velocity
assume the fullback runs to the right and the tackle runs to the left

a) p = mv
p = (9.5kg)(8.2m/s)
p = 77.9 kgm/s

b) p = mass * changing velocity
the fullback's final velocity is 0m/s
p = 9.5 kg ( 0m/s - 8.2m/s)
p = -77.9 kgm/s

c) Momentum is conserved. Because they both end up with 0m/s, the tackle's momentum has to be equal to the fullback 's momentum. Therefore, the tackle changing momentum's is 77.9 kgm/s.

d) -77.9kgm/s

e) -77.9kgm/s = (128kg)v
v = -0.609m/s

hope this helps

Answer 2

I assume that was 95kg, not 9.5kg.

Momentum of FB
p=mv

p=95x8.2
p=779 kgm/s

If final collision velocity is zero, then momentums must have been equal.

original Momentum for DT = 779

779=128 x V
v= 779/128
v=6.09 m/s

Change in momentum for both must have been -779 kgm/s

Hope your answers are here.

Answer 3

earlier: FULLBACK HAS MOMENTUM OF (95X8.2=779) DEFENDER MOMENTUM UNKNOWN AFTER: FULLBACK AS 0 MOMENTUM (95X0=0) DEFENDER HAS 0 MOMENTUM (128X0=0) C) THE substitute IN FULLBACK MOMENTUM IS very final MOMENTUM - preliminary MOMENTUM....0-779= -779 D) THE DEFENDER HAD the comparable substitute IN MOMENTUM yet opposite IN sign (SO somewhat of -779, HIS substitute became 779), via CONSERVATION OF MOMENTUM E) THE DEFENDERS unique MOMENTUM would desire to have been 779 F) via fact MOMENTUM=M*V....THE EQUATION appears like 779=128V.....OR the unique speed IS 6.09