College

You are helping with some repairs at home. You drop a hammer, and it hits the floor at a speed of 12 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. 8.5 feet
B. 1.0 foot
C. 18.0 feet
D. 2.25 feet

Answer :

To solve for the height from which the hammer was dropped, we can use the formula that relates velocity, acceleration due to gravity, and height:

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

where:
- [tex]\( v \)[/tex] is the final velocity (12 feet per second in this case),
- [tex]\( g \)[/tex] is the acceleration due to gravity (32 feet per second squared),
- [tex]\( h \)[/tex] is the height above the ground.

We need to find [tex]\( h \)[/tex]. Start by squaring both sides of the formula to eliminate the square root:

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

Next, solve for [tex]\( h \)[/tex] by dividing both sides by [tex]\( 2g \)[/tex]:

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

Now, plug in the given values:

- [tex]\( v = 12 \)[/tex] feet per second,
- [tex]\( g = 32 \)[/tex] feet per second squared.

[tex]\[ h = \frac{12^2}{2 \times 32} \][/tex]

[tex]\[ h = \frac{144}{64} \][/tex]

[tex]\[ h = 2.25 \][/tex]

Therefore, the hammer was dropped from a height of 2.25 feet above the ground. The correct answer is:

D. 2.25 feet