2D motion help!

[OnlyThorns]

Ok, so five people have tried to explain this to me but I don't get it. Please help me.

 

A car drives striaght off the edge of a cliff that is 46m high. The police at the scene of the accident note that the point of impact is 138m from the base of the cliff. How fast was the car traveling when it went over the cliff?

 

 

I need in-depth detail. I cannot get it.

thanks.

~onlythorns

[Flunch]

When something falls while it is moving horizontally you can consider its motion in both the vertical and horizontal directions SEPARATELY.

 

i.e. it's like dropping the car 46 meters from rest PLUS making the car move forward 138 metres in a separate event.

 

So this car is going to fall vertically 46 metres. Use your motion formula to calculate how long it will take to fall straight down 46 metres from rest to the ground below.

 

d = 1/2*a*t^2

 

remember a is the acceleration due to gravity here.

 

now you'll have the time it took for this car to fall. This is also the time it takes the car to travel 138 metres to rest from the edge of the cliff out, in a horizontal direction.

 

Knowing this you determine the speed of the car when it left the cliff using the basic equation v = d/t.

 

Make sense?