Question

A hot air balloon went from an elevation of 5,275 feet to an elevation of 3,128 feet in 38 minutes. What was its rate of descent? The rate of the descent was BLANK feet per minute.

Answer 1

Given:

Elevation = 5275 feet

New elevation = 3128 feet

Time = 38 minutes

To Find:

Rate of the descent

Solution:

Rate of descent describes the fastest rate at which hot air balloon descends.

Calculating displacement -

= 5275 - 3128 ( As it changed)

= 2147

Thus, displacement is 2147 feet.

Now,

Time taken is = 38 minutes. Converting into seconds

= 38 x 60

= 2280

Therefore, the rate of descent is:

= Displacement / Time taken

= 2147 / 2280

= 0.942

Answer: The rate of descent is 0.942 ft/s

Answer 2

Given

$h_i$ = Initial height of balloon = 5275 feet

$h_f$ = Final height of balloon = 3128 feet

t = Time taken to descend = 38 minutes

To find

Rate of descent of the balloon

Solution

Change of height with respect to time is given by

$r=\dfrac{h_i-h_f}{t}$

$\Rightarrow r=\dfrac{5275-3128}{38}$

$\Rightarrow r=56.5\ \text{ft/min}$

The rate of descent of the balloon was $56.5\ \text{ft/min}$.