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(a) Moment of inertia

(b) Newton’s second law of motion

(c) Newton’s third law of motion

(d) Newton’s law of gravitation

Fill in the blanks [Average]

1. To every __________ there is an __________ and __________, ______________.

2. Action and reaction forces acts on ___________ bodies.

SUBJECTIVE

1. How are able to walk on ground and swim in water? [Board]
2. How rockets and Jet-aero planes work? [Board]

3.Why firemen finds it difficult to hold a hose pipe? [Board and Hots]
4. Why a gun recoils? What is the velocity called? [Board]

NUMERICALS
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1. A car of mass 1000 kg is moving with a velocity of 10 ms and is acted upon by a
forward force of 1000 N due to engine and retarding force of 500 N due to friction. What
will be its velocity after 10 seconds?
-1
2.A bullet of mass 0.04 kg moving with a speed of 90 ms enters a heavy wooden block
and is stopped after a distance of 60 cm What is the average resistive force exerted by
the block on the bullet?
-1
3. A scooterist moving with a speed of 36 kmh sees a child standing in the middle of
the road. He applies the brakes and brings the scooter to rest in 5 s just in time to save
child. Calculate the average retarding force on the vehicle, if mass of the vehicle and
driver is 300 kg.
-2
4.A force of 5 N gives a mass an acceleration of 8 ms and a mass m 2 an acceleration
-2
of 24 ms . What acceleration would it give if both the masses are tied together?