- #1

afg_91320

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## Homework Statement

A ball rolls down a roof that makes an angle of 30 degrees to the horizontal. It rolls

off the edge woth speed of 5.00 m/s. The distance to the ground from that point is 7.00 m.

a) How long is the ball in the air for?

b) How far from the base of the house does it land?

c) What is its speed before landing?

## Homework Equations

[tex]\vartheta[/tex] = 30 degrees

speed = 5.00 m/s

distance from ground to point ball being dropped (roof) = 7.00 m

## The Attempt at a Solution

a) time in the air:

y = -7.00m

v

_{x0}=5.00 m/s

a

_{x}= 0 <- drop so acceleration is 0..correct?

v

_{y0}= 0

a

_{y}= -g <---gravity

x

_{0}and y

_{0}= 0

y = - 1/2 gt

^{2}

t = sqrt [(2y)/(-g) = sqrt [(2)(-7.00)/(-9.80) = 1.2 s <--ball in the air for

b) far from the base of the house:

x = v

_{x0}t = (5.00)(1.2) = 6 m<---- distance from base of the house

c) i don't know how to find the speed-do i need the angle in this equation?