Questions: Wanda runs up a hill that makes an angle of 15.5 degrees above the horizontal. The hypotenuse of the hill is 221 meters long. If Wanda has a mass of 72 kg and she does this in 131 seconds, how many horsepower does she generate?
0.59 hsp
0.64 hsp
0.51 hsp
0.43 hsp
Transcript text: Wanda runs up a hill that makes an angle of 15.5 degrees above the horizontal. The hypotenuse of the hill is 221 meters long. If Wanda has a mass of 72 kg and she does this in 131 seconds, how many horsepower does she generate?
0.59 hsp
0.64 hsp
0.51 hsp
0.43 hsp
Solution
Solution Steps
Step 1: Calculate the Vertical Height of the Hill
To find the vertical height \( h \) of the hill, we use the sine function:
\[
h = 221 \sin(15.5^\circ)
\]
Using a calculator:
\[
h \approx 221 \times 0.2672 \approx 59.0552 \text{ meters}
\]
Step 2: Calculate the Work Done
The work done \( W \) by Wanda is given by:
\[
W = mgh
\]
where \( m = 72 \) kg, \( g = 9.81 \) m/s\(^2\), and \( h = 59.0552 \) meters. Substituting these values:
\[
W = 72 \times 9.81 \times 59.0552 \approx 41700 \text{ joules}
\]
Step 3: Calculate the Power in Watts
Power \( P \) is the work done divided by the time \( t \):
\[
P = \frac{W}{t} = \frac{41700}{131} \approx 318.3206 \text{ watts}
\]
Step 4: Convert Power to Horsepower
1 horsepower (hsp) is equal to 745.7 watts. Therefore, the power in horsepower is:
\[
\text{Power in hsp} = \frac{318.3206}{745.7} \approx 0.4268 \text{ hsp}
\]