Question

A 50 kg man is running at a speed of 18kmph if all the kinetic energy of the man can be used to increase the temperature of watet from 20°c to30°c how much water can be heated with this energy

Answer 1

Hey dear,

● Answer-
m = 149.5 g

● Explanation-
# Given-
M = 50 kg
v = 18 kmph = 5 m/s
∆T = 30-20 = 10 °C
c = 4.18 J/g°C

# Solution-
Here,
K.E.(man) = 1/2 Mv^2
K.E.(man) = 1/2 × 50 × 5^2
K.E.(man) = 625 J

This energy is used to heat water-
Q = m.c.∆T
625 = m × 4.18 × 10
m = 625 / 41.8
m = 149.5 g

We can heat 149.5 g of water using KE of man.

Hope this helps...