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

Answer :

To find the height ( [tex]\( h \)[/tex] ) from which the hammer was dropped, we can use the formula:

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

where:
- [tex]\( v \)[/tex] is the final speed of the hammer when it hits the ground, 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 from which the hammer was dropped.

First, let's rearrange the formula to solve for [tex]\( h \)[/tex]:

1. Square both sides to eliminate the square root:
[tex]\[
v^2 = 2gh
\][/tex]

2. Solve for [tex]\( h \)[/tex]:
[tex]\[
h = \frac{v^2}{2g}
\][/tex]

Substitute the known values into the equation:

- [tex]\( v = 8 \)[/tex] feet per second
- [tex]\( g = 32 \)[/tex] feet per second squared

3. Plug in these values:
[tex]\[
h = \frac{8^2}{2 \times 32}
\][/tex]

4. Calculate [tex]\( 8^2 \)[/tex]:
[tex]\[
8^2 = 64
\][/tex]

5. Calculate [tex]\( 2 \times 32 \)[/tex]:
[tex]\[
2 \times 32 = 64
\][/tex]

6. Now, divide the results:
[tex]\[
h = \frac{64}{64} = 1.0
\][/tex]

Therefore, the hammer was dropped from a height of 1.0 foot. The correct answer is C. 1.0 foot.