Question

When two blocks collide, they each experience the same magnitude...(click ALL the correct responses)

a- force

b- Impulse

c- change in momentum

d- change in velocity

Answer 1

When two blocks collide, and there is no external force applied on the system, then momentum of system before and after collision remains conserved, So

Pi = Pf

m1*u1 + m2*u2 = m1*v1 + m2*v2

m1 = mass of 1st block & m2 = mass of 2nd block, So

m1*(v1 - u1) = m2*(u2 - v2)

m1*(v1 - u1) = -m2*(v2*u2)

(We know that momentum = mass*Velocity), So taking magnituded on both sides gives

m1*(v1 - u1) = |-m2*(v2*u2)|

So, change in momentum will be same for both blocks

Now impulse is given by:

Impulse = change in momentum

J = dP = m*dV = m*(Vf - Vi)

Since change in momentum is same for both blocks, So Impulse will also be same

Now force experienced by both blocks will also be same, Since

Average force = Impulse/Impact time = J/dt

F_avg = m*dV/dt

Again since change in momentum is same for both blocks, So force will also be same

Since both blocks can have different mass, So in that case change in velocity will not be same for both blocks

So, Correct option is A, B, C

Let me know if you've any query.