# Kinematcis, archer and his arrow

1. Aug 16, 2012

### alicia113

An archer shoots an arrow straight up into the air with an initial velocity of 45 m/s . Calculate the maximum height of the arrow.

The equation I would use for this is:
Vf^2 = Vo^2+2as

where:
Vf is final velocity
Vo is initial velocity
a is acceleration (gravity)
s is displacement

plug in the numbers we know:
0^2 = 45^2 + 2(-9.8)s

now solve for s

0=2025-19.6s
-2025=-19.6s

s = 103.32 meters.

is this right

2. Aug 16, 2012

### CAF123

Yes.
I would say it is best to rearrange the equation to make $s$ the subject first and then substitute numbers.

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