Question

A lift in a mine moves down 24 m in 87 mins. If it moves in uniform rate, find at what distance below the surface it will be after 6 mins. If the lift starts from a height 10 m above the ground find how deep the lift will go from the surface after 70 mins.

Answer 1

Answer:

If 24m is moved in 87 min, then speed of lift is 24/87 = 0.276 m/min

So, after 6 min, the lift is 0.276x6 = 1.656m below.

If the lift starts 10m above, then it touches the ground after 10/0.276 = 36.232 min

Then, the rest 70-36.232 = 33.768 min is spent below. So, it moves 0.276x 33.768 = 9.32m at this time.

Hence, after 70 mins the lift goes 9.32m deep.

Answer 2

Answer:

If 24m is moved in 87 min, then speed of lift is 24/87 = 0.276 m/min

So, after 6 min, the lift is 0.276x6 = 1.656m below.

If the lift starts 10m above, then it touches the ground after 10/0.276 = 36.232 min

Then, the rest 70-36.232 = 33.768 min is spent below. So, it moves 0.276x 33.768 = 9.32m at this time.

Hence, after 70 mins the lift goes 9.32m deep.