Question

A person carrying 10 bricks each of mass 2.5 kg on his head moves to a height 20 m in 50 seconds . Calculate the power spent in carrying bricks of the person. (g = 10 m/s 2)

Answer 1

mass of 10 bricks= 2.5×10
=25 kg
power=work done ×displacement/time
=25×10×20/50
=100W

Answer 2

Given,

Total number of bricks carried = 10

Mass of each brick = 2.5 Kg

The total increase in elevation level of the person = 20 m

Time taken. = 50 s

To find,

The power spent by the person in carrying the bricks.

Solution,

We can simply solve this numerical problem by using the following process:

Mathematically,

Power = (total work done)/(time taken)

= (total mass×height×acceleration due to gravity)/(time taken)

Now,

The total mass of all the bricks carried

= (mass of each brick)×(total number of bricks)

= 2.5 Kg × 10 bricks

= 25 Kg

Now, according to the question;

The power spent by the person in carrying the bricks

= (total mass×height×acceleration due to gravity)/(time taken)

= (25 Kg × 20 m × 10 m/s 2)/(50 s)

= (5000 Kg.m^2/s^2)/(50 s)

= 100 W

Hence, the total power spent by the person in carrying the bricks is equal to 100 W.