# Projectile motion question

## Homework Statement

A car collides with a brick wall and comes to rest.
A parcel which was on top of the roof at the time becomes detached. It is initially traveling horizontally and it strikes the ground a distance of 12m from the point where it left the car. The parcel is initially 1.5 m above ground.

What period of time elapses before the parcel strikes the ground?

Estimate the speed of the car just before it collided with the wall?

s=ut+1/2at^2
v=u+at
v^2=u^2+2as

## The Attempt at a Solution

i have no idea where to start, ??

Last edited:

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learningphysics
Homework Helper
You need the velocity with which the car collided?

How long does it take the parcel to fall 1.5m?

Use this time with the 12m to get the horizontal velocity.

yes, thats what i initially thought as iv'e tried working this out..... the velocity was not provided..?

learningphysics
Homework Helper
yes, thats what i initially thought as iv'e tried working this out..... the velocity was not provided..?

no it wasnt, i havent made any sufficient steps..

learningphysics
Homework Helper
no it wasnt, i havent made any sufficient steps..
First step, find the time it takes to drop 1.5m.

this is the vertical direction. initial vertical velocity = 0

try to apply:

d = v1*t + (1/2)at^2

to this situation.

thankyou!

learningphysics
Homework Helper
thankyou!
no prob.