-A Block of Mass M = 7

Multiple Choice

-A block of mass m = 7.6 kg,moving on a frictionless surface with a speed v_i = 7.6 m/s,makes a perfectly elastic collision with a block of mass M at rest.After the collision,the 7.6 kg block recoils with a speed of v_f = 2.5 m/s.In the figure,the blocks are in contact for 0.20 s.The average force on the 7.6 kg block,while the two blocks are in contact,is closest to:

A) 384 N
B) 336 N
C) 289 N
D) 241 N
E) 194 N