- #1

HaLAA

- 85

- 0

## Homework Statement

A ball is thrown toward a cliff of height h with a speed of 28.0 m/s and an angle of 60.0° above horizontal.

What is the ball's impact speed

## Homework Equations

Vf=Vi-at

Sf=Si+Vit-1/2gt^2

Vy=sintheta

Vx=costheta

## The Attempt at a Solution

first find the vertical velocity = 28 sin 60 = 24.25m/s

find time to maximum height from Vf = Vi+ at

0 = 24.25 - 9.8t

t = 2.47sec

the height reached

v^2 = u^2 + 2as

0 = 24.25^2 - 2 x 9.81 s

s = 29.97m

the ball must drop for 3.5 - 2.47 sec = 1.03s

find the height it falls s = 1/2 at^2

s = 0.5 x 9.8 x 1.03^2

s = 5.2m

the impact speed is 5.2m /1.03s= 5.05m/s