High School

You are helping with some repairs at home. You drop a hammer, and it hits the floor at a speed of 4 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. 0.5 feet
B. 1.0 foot
C. 0.25 feet
D. 16.0 feet

Answer :

To determine how far above the ground the hammer was when it was dropped, we use the formula:

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

where:
- [tex]\( v \)[/tex] is the speed at which the hammer hits the ground (4 feet per second),
- [tex]\( g \)[/tex] is the acceleration due to gravity (32 feet per second squared),
- [tex]\( h \)[/tex] is the height above the ground.

We want to find [tex]\( h \)[/tex], so we'll rearrange the formula:

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

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

Substitute the given values into the equation:

- [tex]\( v = 4 \)[/tex] feet per second
- [tex]\( g = 32 \)[/tex] feet per second squared

Calculate [tex]\( h \)[/tex]:

[tex]\[ h = \frac{(4)^2}{2 \times 32} \][/tex]

[tex]\[ h = \frac{16}{64} \][/tex]

[tex]\[ h = 0.25 \text{ feet} \][/tex]

Therefore, the hammer was dropped from a height of 0.25 feet above the ground. The correct answer is C. 0.25 feet.