Question

A car runs of a road and collides with a tree. glass pieces from the windscreen are projected forward and are found an average distance of 12m from the car. the average height of the windscreen is 1.2m.

Establish the speed of the car at the time of impact. assume g=10 m/s²​

Answer 1

v₀ₓ = 24.24 m / s

Step-by-step explanation:

This is a projectile launching exercise, where the windshield comes out with a horizontal initial velocity.

Y axis

initial vertical velocity is zero

y = y₀ + v_{oy} t - ½ g t²

when it reaches the ground its height is zero and the initial height is y₀=1.2m

0 = y₀ + 0 - ½ g t²

t =
`√(2 y_o/g)`

t =
`√(2 \ 1.2 / 9.8)`

t = 0.495 s

X axis

x = v₀ₓ t

v₀ₓ = x / t

v₀ₓ = 12 / 0.495

v₀ₓ = 24.24 m / s