Question

a car of mass 1000kg moving with a velocity of 36km/h colloids with a tree and comes to rest in 5sec what will be the force exerted by the car on the tree

Answer 1

Mass of the car = 1000 kg

Initial velocity of car (u) = 36 km/hr = 10 m/s

Final velocity of car (v) = 0 m/s (coming to rest)

Time taken by the car to come to rest (t) = 5 s

Let the acceleration be a.

Using first equation of motion:

v = u + at

$a = \frac{v-u}{t}$

$a = \frac{10}{5}$

a = 2 m/s^2

Now, Force applied by the tree = mass × acceleration

Force = 1000 × 2

Force = 2000 N

Hence, the force applied by the tree on the car is 2000 N