To find the accelerations a1 and a2 of the two masses, we use the formula for distance covered in the nth second:
Sn=u+2a(2n−1)
For the first mass (m1=3.4 kg, u1=5 m/s):
104=5+2a1(2⋅5−1)
99=29a1⟹a1=22 m/s2
For the second mass (m2=2.5 kg, u2=12 m/s):
129=12+2a2(2⋅5−1)
117=29a2⟹a2=26 m/s2
Next, we calculate their velocities after t=10 s using v=u+at:
v1=5+22(10)=225 m/s
v2=12+26(10)=272 m/s
The momenta p1 and p2 after 10 s are:
p1=m1v1=3.4×225=765 kg⋅m/s
p2=m2v2=2.5×272=680 kg⋅m/s
Taking the ratio of their momenta:
p2p1=680765=89
Given that p2p1=8x, we get:
x=9