High School

You are helping with some repairs at home. You drop a hammer, and it hits the floor at a speed of 8 feet per second. If the acceleration due to gravity ([tex]g[/tex]) is 32 feet/second[tex]\(^2\)[/tex], how far above the ground ([tex]h[/tex]) was the hammer when you dropped it?

Use the formula: [tex]v = \sqrt{2gh}[/tex]

A. 2.0 feet
B. 16.0 feet
C. 8.0 feet
D. 1.0 foot

Answer :

To solve the problem of finding how far above the ground the hammer was when you dropped it, we will use the given formula:

[tex]\[ v = \sqrt{2gh} \][/tex]

where:
- [tex]\( v \)[/tex] is the speed of the hammer when it hits the floor, which is 8 feet per second.
- [tex]\( g \)[/tex] is the acceleration due to gravity, which is 32 feet per second squared.
- [tex]\( h \)[/tex] is the height above the ground we need to find.

We first rearrange the formula to solve for [tex]\( h \)[/tex]:

[tex]\[ v = \sqrt{2gh} \][/tex]

Square both sides to remove the square root:

[tex]\[ v^2 = 2gh \][/tex]

Now solve for [tex]\( h \)[/tex]:

[tex]\[ h = \frac{v^2}{2g} \][/tex]

Substitute the known values into the equation:

[tex]\[ h = \frac{8^2}{2 \times 32} \][/tex]

First, calculate [tex]\( 8^2 \)[/tex]:

[tex]\[ 8^2 = 64 \][/tex]

Then multiply [tex]\( 2 \times 32 \)[/tex]:

[tex]\[ 2 \times 32 = 64 \][/tex]

Now divide the value of [tex]\( 8^2 \)[/tex] by [tex]\( 64 \)[/tex]:

[tex]\[ h = \frac{64}{64} = 1.0 \][/tex]

Therefore, the hammer was 1.0 foot above the ground when it was dropped. Hence, the correct answer is:

D. 1.0 foot