Question

question 13
2 pts
if it took 2 minutes to hoist an aircraft weighing 1500 lbs to a vertical height of 7 feet what is the horsepower required for this?
○ .45
○ .026
○ .16

Explanation:

Step1: Recall the formula for work and power

Work \( W \) is calculated as force \( F \) times distance \( d \), so \( W = F \times d \). Here, the force is the weight of the aircraft, \( F = 1500 \) lbs, and the distance \( d = 7 \) feet. Then, power \( P \) in foot - pounds per minute is \( P=\frac{W}{t}\), and to convert to horsepower (hp), we use the conversion factor: 1 hp = 33000 foot - pounds per minute.

First, calculate the work done:
\( W=F\times d = 1500\space lbs\times7\space ft=10500\space foot - pounds\)

Step2: Calculate power in foot - pounds per minute

The time \( t = 2\) minutes. So the power \( P\) in foot - pounds per minute is:
\( P=\frac{W}{t}=\frac{10500\space foot - pounds}{2\space minutes}=5250\space foot - pounds\space per\space minute\)

Step3: Convert power to horsepower

We know that 1 hp = 33000 foot - pounds per minute. So the horsepower \( HP\) is:
\( HP=\frac{5250}{33000}\approx0.16\) (rounded to two decimal places)

Answer:

.16