Question

Question 5) How much work is done in raising 1 tonne of
coal from a mine 300 m deep.​

Answer 1

m=10

5

kg,g=10ms

−2

,h=360m,t=1h=3600s

The work needed in lifting a mass m to a height h against the force due to gravity is W=mg×h

And, power, P=

t

W

=

t

mgh

∴P=

3600

10

5

×10×360

W=10

5

W=100kW

Answer 2

Answer:

2940000

Explanation:

I Tonne=1000kg

now,

force=ma

=1000×9.8

=9800N

WORK DONE =FORCE × displacement

=9800×300

=2940000Nm