Stunt Car Jump: How Far and How Fast? | Solving for Distance and Impact Speed"

[AvrGang]

Homework Statement

A stunt man drives a car at a speed of 20 m/s off a 30-m-high cliff.
The road leading to the cliff is inclined upward at an angle of 20(degrees).
a. How far from the base of the cliff does the car land?
b. What is the car's impact speed?

Homework Equations

The Attempt at a Solution

Here is my solving:

Vix=Vicos@
=20cos20
=18.8m/s

Viy=Visin@
=20sin20
=6.84m/s

a) How far from the base of the cliff does the car land?
x=Vix t
x=18.8t ------(1)

y=Viy t - 1/2gt^2
-30=6.84t-0.5(9.8)t^2
-4.9t^2+6.84t+30=0 (divide this by -4.9)
t^2-1.39t+30=0
From this equation we can find t then sustitute its magnitude in equation 1, so we can find x

b)speed=sqrt((Vfx)^2+(Vfy)^2)

 

[AvrGang]

sqrt is square root