Question

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Question 2
(a) A crane 'A' lifts a heavy load in 5 seconds, whereas another crane 'B' does the
same work in 2 seconds. Compare the power of crane 'A' to that of crane 'B'.​

Answer 1

Answer:

Power = Work done / time

Here, work done is same. That is. W.(let)

So, For crane A, Power, P(A) = W / 5

For crane B, Power, P(B) = W /2

P(A) /P(B) = (W/5)(W/2)

Answer : P(A) /P(B) = 2/5

Answer 2

Answer:

The power of crane 'A' to that of crane 'B' is in the ratio of 2:5.

Explanation:

Given:

Time taken by the crane A(Ta)=5 seconds

Time taken by the crane B(Tb)=2 seconds

The amount of work done is the same

To find: Ratio of power of  crane 'A' to that of crane 'B'.​

Solution:
We know that, Power can be calculated using the formula

$Power=\frac{Work}{Time}$

∴Pa/Pb=Tb/Ta

∴Pa/Pb=2/5

Therefore, the power of crane 'A' to that of crane 'B' is in the ratio of 2:5.