Question

the driver of with three wheeler moving with a speed of 10 metre per second sees a child standing in the middle of the road at the distance of 10m. he applies brakes and bring the vehicle to rest in front of boy if the mass of bike and man is 450 kg .find the brake force

Answer 1

initial speed = u = 10m/s
final speed = v = 0m/s
distance = s = 10m
acceleration = a = ?

v²-u² = 2as
(0²-10²) = 2(a)(10)
-100 = 20a
-100/20 = a
-5 m/s² = a

here - show that uniform acceleration
so acceleration of three wheeler van is 5m/s²

total mass = m = 450kg
F = ma

F = 450×5

F = 2250N

so the force of the break is 2250 Newton