All Solved Numerical of Chapter 5
1. A man pulls a trolley through a distance of
10 m by applying a force of 50 N which makes an angle of 600 with the
horizontal. Calculate the work done by the man?
(Ans: 250 J)
2. A 100 kg man runs up a long flight of stairs
in 9.8 second. The vertical height of the stair is 10 m. Calculate its power?
(Ans: 1000 Watts)
3. When an object is thrown upwards. It rises
to a height ‘h’. How high is the object in
terms of h. when ii has lost one third of its
original kinetic energy? (Ans: h/3)
4. A 70 kg man runs up a bill through a height
of 3 m in 2 seconds.
(a) How much work does he do against
gravitational field?
(b) What is the average power output? (Ans:
2060 1. 1030 Watt)
5. A neutron travels a distance of 12 m in a
time interval of 3.6 x 10 sec. Assuming its speed was constant, Find its
kinetic energy? Take the mass of neutron 1.7 x 10-27 kg.
(Ans: 5.78 c V)
6. A stone is thrown vertically upwards and can
reach to a height of 10m, find the speed
of stone, when it is just 2m above the ground? (Ans: 12.9 m/s)
7. The potential energy of a body at the top of
a building is 200 Joules when itls dropped its kinetic energy just before
striking the ground is 160 Joules, find the work done against the air
resistance? (Ans: 40 J)
8. Find the energy equivalent of 1 gram? (Ans:
9 x 1013J)
9. A 1 Kilowatt motor pump, pumps the water
from the ground to a height of 10 m. Find, how much liters of water it can pump
in one hour? (Ans: 3.6x104 litre)
10. A rocket of mass 2kg is launched in air,
when it attains height of I 5m the 400 Joules of its chemical fuel burns. Find
the speed of rocket at maximum height? (Ans: 10 m/s)
11. A motor pumps the water at the rate 500
gram/minute to the height of 120 in. If the motor is 50% efficient then how
much input electric power is needed? (Ans: 20 watt)
Comments
Post a Comment