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प्रश्न
Newton’s III law is applicable
विकल्प
for a body is at rest
for a body in motion
both a & b
only for bodies with equal masses
उत्तर
Both a & b
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संबंधित प्रश्न
A 8000 kg engine pulls a train of 5 wagons, each of 2000 kg. along a horizontal track. If the engine exerts a force of 40000 N and the track offers a friction force of 5000 N, then calculate:
- the net accelerating force and
- the acceleration of the train.
An automobile vehicle has a mass of 1500 kg. What must be the force between the vehicle and road if the vehicle is to be stopped with a negative acceleration of 1.7 m s−2?
An object of mass 100 kg is accelerated uniformly from a velocity of 5 ms−1 to 8 ms−1 in 6 s. Calculate the initial and final momentum of the object. Also, find the magnitude of the force exerted on the object.
How much momentum will a dumb-bell of mass 10 kg transfer to the floor if it falls from a height of 80 cm? Take its downward acceleration to be 10 m s−2.
A large truck and a car, both moving with a velocity of magnitude v, have a head-on collision and both of them come to a halt after that. If the collision lasts for 1 s:-
(a) Which vehicle experiences the greater force of impact?
(b) Which vehicle experiences the greater change in momentum?
(c) Which vehicle experiences the greater acceleration?
(d)Why is the car likely to suffer more damage than the truck?
Fill in the following blanks with suitable words :
Newton’s second law of motion can be written as Force = mass × _____________ or Force = _____________ of change of _____________.
Explain the meaning of the following equation :
F = m x a
where symbols have their usual meanings
Complete a sentence and explain it.
During a collision, ______ remains constant.
State Newton’s second law.
Using the second law of motion, derive the relation between force and acceleration. A bullet of 10 g strikes a sand-bag at a speed of 103 m s-1 and gets embedded after travelling 5 cm. Calculate
(i) the resistive force exerted by the sand on the bullet
(ii) the time is taken by the bullet to come to rest.
