Question

A 50 kg man is running at a
speed of 18kmh. If all the
kinetic energy of the man
can be used to increase the
temperature of water 20°C to
30°C , then the amount of
water that can be heated
with this energy is
(approximately)​

Answer 1

Answer:

Given,

Mass = 50kg

Velocity = 18km/hr = 5m/s

Initial temperature = (Ti) = 20°C

Final temperature (Tf) = 30°C

Temperature change = Tf - Ti

= 30°-20° = 10°C

Specific heat capacity (C) = 4.18J/g°C

To find:-

Kinetic energy and Mass

We know that, K.E = 1/2mv^2

= 1/2×50×5×5

= 25×25

= 625J

Specific heat, Q = m.c.ΔT

625 = m×4.18×10

625 = 41.8m

m = 14.95g.