Question

The thickness of a hollow metallic cylinder is 2cm. It is 42cm long and its
inner radius is 10 cm. Find the volume of metal required to make the
cylinder, assuming it is open at both the ends.

Answer 1

Step-by-step explanation:

Given:-

Rate of descending the elevator = 7m/min

It start descend from 9 m above the ground level.

To Find:-

How long will it take to reach -205 m

Solution:-

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀According to the Question

It is given that elevator descends in to a mine shaft at the rate of 7m/min .If its descent starts from 9m above the ground level. we have to calculate the time taken to reach -205 m . So let's begin

As the elevator descend 9 m above from the ground level.

So , the distance descended by the elevator = -205 + (+9)

:\implies:⟹ -196m

Now it is given that the rate of descending the elevator is 7m/min. (we take the rate of descending in negative )

Let the time taken by the elevator be t min .

Therefore,

:\implies:⟹ rate = Distance/time

Substitute the value we get

:\implies:⟹ -7 = -196/t

:\implies:⟹ 7 = 196/t

:\implies:⟹ 7×t = 196

:\implies:⟹ t = 196/7

:\implies:⟹ t = 28 minutes

Hence, the time taken by the elevator is 28 minutes.

Answer 2

Step-by-step explanation:

Volume of hollow cylinder = π(r12−r22)h=227(142−122)35=22(196−144)5=110×52=5720cm3 . Hence, the volume of metal required to make the hollow cylinder is 5720cm3 . Sorry!, This page is not available for now to bookmark. Bookmark added to your notes