Question 1 :
Using a horizontal force of 200 N, we intend to move a wooden cabinet across a floor at a constant velocity. What is the friction force that will be exerted on the cabinet?
Question 2 :
Water sprinkler used for grass lawns begins to rotate as soon as the water is supplied. Explain the principle on which it works.
Question 3 :
A motorcar of mass 1200 kg is moving along a straight line with a uniform velocity of 90 km/h. lts velocity is slowed down to 18 km/h in 4 s by an unbalanced external force. What is the magnitude of the force required?
Question 4 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2e3f59b460d7261f64d.jpg' />
The above image is the distance-time table of an object in motion. What conclusion can you draw about the acceleration? Is it constant, increasing, decreasing, or zero?
Question 5 :
An object of mass 2 kg is sliding with a constant velocity of $4ms^{-1}$ on a frictionless horizontal table. The force required to keep the object moving with the same velocity is
Question 6 :
A batsman hits a cricket ball which then rolls on a level ground. After covering a short distance, the ball comes to rest. The ball slows to a stop because
Question 7 :
A motorcar of mass 1200 kg is moving along a straight line with a uniform velocity of 90 km/h. lts velocity is slowed down to 18 km/h in 4 s by an unbalanced external force. What is the change in momentum?
Question 8 :
A truck starts from rest and rolls down a hill with a constant acceleration. It travels a distance of 400 m in 20 s. What is the force acting on it if its mass is 7 tonnes?
Question 9 :
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 what is the net accelerating force?
Question 10 :
An object of mass 1 kg travelling in a straight line with a velocity of 10 m/s collides with, and sticks to, a stationary wooden block of mass 5 kg. Then, they both move off together in the same straight line. What is the total momentum just before the impact and just after the impact?
Question 11 :
An object of mass 1 kg travelling in a straight line with a velocity of 10 m/s collides with, and sticks to, a stationary wooden block of mass 5 kg. Then, they both move off together in the same straight line. What is the velocity of the combined object?
Question 12 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2e3f59b460d7261f64e.jpg' />
The above image is the distance-time table of an object in motion. What do you infer about the forces acting on the object?
Question 14 :
Two friends on roller-skates are standing 5 m apart facing each other. One of them throws a ball of 2 kg towards the other. How will this activity affect the position of the two? Explain your answer.
Question 16 :
Two balls of the same size but of different materials, rubber and iron are kept on the smooth floor of a moving train. The brakes are applied suddenly to stop the train. Will they move with the same speed?
Question 17 :
A goalkeeper in a game of football pulls his hands backwards after holding the ball shot at the goal. This enables the goal keeper to
Question 18 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d283f59b460d7261f5cb.png' />
Velocity versus time graph of a ball of mass 50 g rolling on a concrete floor is shown in the figure. Calculate the acceleration of the floor on the ball.
Question 19 :
Two identical bullets are fired one by a light rifle and another by a heavy rifle with the same force. Which rifle will hurt the shoulder more?
Question 20 :
Two persons manage to push a motor car of mass 1,200 kg at a uniform velocity along a level road. The same motor car can be pushed by three persons to produce an acceleration of 0.2 $ ms^{-2}$. With what force does each person push the motor car? (Assume that all persons push the motor car with the same muscular effort).
Question 21 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d284f59b460d7261f5cc.png' />
Velocity versus time graph of a ball of mass 50 g rolling on a concrete floor is shown in the figure. Calculate the frictional force of the floor on the ball.
Question 22 :
A horse continues to apply a force in order to move a cart with a constant speed because the force applied by the horse balances the force of friction.
Question 23 :
From a rifle of mass 4 kg, a bullet of mass 50 g is fired with an initial velocity of 35 m/s. What is the initial recoil velociy of the rifle?
Question 24 :
Two balls of the same size but of different materials, rubber and iron are kept on the smooth floor of a moving train. The brakes are applied suddenly to stop the train. Will the balls start rolling? If so, in which direction?
Question 25 :
There are three solids made up of aluminium, steel and wood, of the same shape and same volume. Which of them would have highest inertia?
Question 26 :
A stone of 1 kg is thrown with a velocity of 20 m/s across the frozen surface of a lake and comes to rest after travelling a distance of 50 m. What is the force of friction between the stone and the ice?
Question 27 :
A passenger in a moving train tosses a coin which falls behind him. It means that motion of the train is
Question 28 :
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 what is the acceleration of the train?
Question 29 :
A bullet of mass 10 g travelling horizontally with a velocity of 150 m/s strikes a stationary wooden block and comes to rest in 0.03 s. What is the distance of penetration of the bullet into the block?
Question 30 :
A hockey ball of mass 200 g travelling at 10 m/s is struck by a hockey stick so as to return it along its original path with a velocity at 5 m/s. What is the magnitude of change of momentum occurred in the motion of the hockey ball by the force applied by the hockey stick?
Question 31 :
Using second law of motion, derive the relation between force and acceleration. A bullet of 10 g strikes a sand-bag at a speed of $10^{3}ms^{-1}$ and gets embedded after travelling 5 cm. Calculate the time taken by the bullet to come to rest.
Question 32 :
A truck of mass M is moved under a force F. If the truck is then loaded with an object equal to the mass of the truck and the driving force is halved, then how does the acceleration change?
Question 33 :
What is the momentum of an object of mass m, moving with a uniform velocity v?
Question 34 :
A hammer of mass 500 g, moving at 50 $ms^{-1}$, strikes a nail. The nail stops the hammer in a very short time of 0.01 s. What is the force of the nail on the hammer?
Question 35 :
Which of the following statement is not correct for an object moving along a straight path in an accelerated motion?
Question 36 :
An object of mass 100 kg is accelerated uniformly from a velocity of 5 m/s to 8 m/s in 6s. What is the initial and final momentum of the object?
Question 37 :
Which of the following has more inertia, a five rupes coin or a one rupee coin?
Question 38 :
A force of 5 N produces an acceleration of 8 $ms^{-2}$ on a mass $m_1$ and an acceleration of 24 $ms^{-2}$ on a mass $m_2$. What acceleration would the same force provide if both the masses are tied together?
Question 39 :
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 $ms^{-2}$?
Question 40 :
According to the third law of motion, action and reaction ___
Question 41 :
Two objects, each of mass 1.5 kg are moving in the same straight line but in opposite directions. The velocity of each object is 2.5 m/s before the collision during which they stick together. What will be the velocity of the combined object after the collision?
Question 42 :
Which of the following has more inertia, a rubber ball or a stone of the same size?
Question 43 :
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 it's downward acceleration to be 10 $ms^{-2}$.
Question 44 :
Which of the following has more inertia, a bicycle or a train?
Question 45 :
An object of mass 100 kg is accelerated uniformly from a velocity of 5 m/s to 8 m/s in 6s. What is the magnitude of the force exerted on the object?
Question 46 :
A motorcar of mass 1200 kg is moving along a straight line with a uniform velocity of 90 km/h. lts velocity is slowed down to 18 km/h in 4 s by an unbalanced external force. What is the acceleration?
Question 47 :
A bullet of mass 10 g travelling horizontally with a velocity of 150 m/s strikes a stationary wooden block and comes to rest in 0.03 s. What is the magnitude of the force exerted by the wooden block on the bullet?
Question 48 :
Two friends on roller-skates are standing 5 m apart facing each other. One of them throws a ball of 2 kg towards the other, what will be the net force of person who catches it?
Question 50 :
Suppose a ball of mass m is thrown vertically upward with an initial speed v, its speed decreases continuously till it becomes zero. Thereafter, the ball begins to fall downward and attains the speed v again before striking the ground. It implies that the magnitude of initial and final momentums of the ball are same. Yet, it is not an example of conservation of momentum. Why?
