Question

A boy of mass 55 kg runs up a flight of 40 stairs ,its measuring 0.15 m. Calculate the work done by the boy.

Answer 1

$p.e = mgh$
$p .e= 40 \times 10 \times 0.15$
$p.e = 60j$
we know that energy is equal to work therefore work is equal to 60j

Answer 2

Answer:

The work done by the boy is 3300 Joules

Step-by-step explanation:

Given,

Mass of boy = 55 kg

Number of stairs = 40

Height of each stair = 0.15 m

Total height covered by the boy =  0.15 * 40 = 6 m

Since we know,

Potential energy is equal to the work done by the body;

P.E = m * g * h

where,

m is the mass of body

g is the gravity

h is the height

Substituting the values,

P.E = 55 * 10 * 6

P.E = 3300 joules

Hence,

The work done by the boy is 3300 Joules