Question

A bucket is raised from a well by means of a rope which is wound round a wheel of diameter 77cm. If the bucket ascents in 1min28sec with a uniform speed of 1.1 mper sec

Answer 1

Time of ascent = 1 minute 28 seconds = 88 seconds
The uniform speed at which the bucket ascents = 1.1 m/s.
So, the height to which the bucket ascents = (88 × 1.1) m
 
Diameter of the wheel, d = 77 cm = 0.77 m
In each revolution of the wheel the bucket ascents a height of its circumference i.e. pi × d = (22/7) × 0.77 m = 22 × 0.11 m.
 
Therefore, the number complete revolution made by the wheel by ascending the bucket up to the height of (88 × 1.1) m = (88 × 1.1) / (22 × 0.11) = 4 × 10 = 40.

Answer 2

Explanation:

Given :

Diameter = 77 cm

Radius = 77/2 = 38.5 cm

Convert it into m = 38.5/100 = 0.385 m

Speed = 1.1 m/s

Time = 1 min 28 Sec = 60 + 28 = 88 sec

Find :

The number of complete revolution.

Solution :

Distance = Speed × Time

➡ 1.1 × 88

➡ 96.8 m

Number of revolution = distance / circumference

$= > \frac{96.8 \times 7 }{2 \times 22 \times 0.385}$

$= > \frac{968 \times7 \times 100}{2 \times 22 \times 0385 \times 10}$

$= > 8 \times 5$

$= > 40.$

Hence :

The number of complete revolution is 40.