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

Answer :

Sure! Let's solve the problem step-by-step using the given formula:

We are given:
- The final speed [tex]\( v \)[/tex] of the hammer when it hits the floor is 8 feet per second.
- The acceleration due to gravity [tex]\( g \)[/tex] is 32 feet/second².

We need to find the height [tex]\( h \)[/tex] from which the hammer was dropped. The formula we are using is:

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

The goal is to solve for [tex]\( h \)[/tex]. We'll start by squaring both sides of the equation to get rid of 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, substitute the known values into the equation:

- [tex]\( v = 8 \)[/tex] feet/second
- [tex]\( g = 32 \)[/tex] feet/second²

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

Calculate [tex]\( 8^2 \)[/tex]:

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

Then, calculate:

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

Finally, divide:

[tex]\[ h = \frac{64}{64} = 1 \][/tex]

So, the height [tex]\( h \)[/tex] from which the hammer was dropped is 1.0 foot.

The correct option is:
A. 1.0 foot