Question

a car traveling at 90km/hr slams into a tree and is stopped in 40ms.if the car has a mass of 800kg , calculate the average force acting on the car during collision
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Answer 1

Answer:

Explanation: solution-:

here,

initial velocity(u)=90km/hr

                            =(90*1000/60*60)m/s

                            =25m/s

final velocity (v) =0m/s

time=40sec

mass(m) =800kg

average force=?

we have, acceleration (a)= v-u/t

                                           =(0-25)/40

                                           =-0.625m/s^2

now, force=m*a

                 =(800*-0.625)

                 =-500n

here, the negative sign means that the force is acting against  tree