Question

an aeroplane was flying at a height of 1800m. if it descends at a constant rate of 60 m per minute. how will it take to descend to a height of 300 m?​

Answer 1

The time taken by aeroplane to descend at a height of 300 M = 25 minutes

The height at which the aeroplane is flying = 1800 M

The rate at which the aeroplane is descending = 60 M

The Height function of aeroplane at any instant of time is given by

H(t) = 1800 - 60·t

Now, we need to calculate the time taken by aeroplane to descend at a height of 300 M

So, putting H(t) = 300 in the height function. We get ,

300 = 1800 - 60·t

⇒ 300 - 1800 = -60·t

⇒ -1500 = -60·t

⇒ 60·t = 1500

⇒ t = 25

Hence, The time taken by aeroplane to descend at a height of 300 M = 25 minutes

Answer 2

height 1800m

speed 60m per minute

descending height = 1800-300

= 1500m

time = distance/ speed

= 1500/60

= 150/6 = 50/2 = 25 mins

IT WILL TAKE A TIME OF 25MINS FOR THE AEROPLANE TO DESCEND TO A

HEIGHT OF 300 M