Question

Question #020f1

Answer 1

Velocity of the car just brfore its impact with the stationary truck is `v_i=2"m/s"` The car comes to rest finally, So its final velocity `v_f=0"m/s"`.The car travels `5m` after its impact.Hence `s=5m`

Using equation of kinematics we can write

`v_f^2=v_i^2-2as`,where `a` is the average retardation produced.

`0^2=20^2-2axx5=>a=40"m/"s^2`

So the force exerted by the seat belt on the passenger of mass `m=90kg` will be

`F=ma=90xx40N=3600N`