Projectile Motion: Calculating Parcel Time and Car Speed

[whitestrat69]

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?

Homework Equations

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, ??

 

[learningphysics]

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.

 

[whitestrat69]

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

 

[learningphysics]

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

can you show your steps? what was the answer given?

 

[whitestrat69]

no it wasnt, i haven't made any sufficient steps..

 

[learningphysics]

no it wasnt, i haven't 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.

 

[whitestrat69]

thankyou!

 

[learningphysics]

thankyou!

no prob.