Impulsive Forces in Collision

Q.

A particle moves in the $XY$ Plane under the action of a force $F$ such that the components of its linear momentum $P$ at any time $t$ are $P_x=2\cos t$, $P_y=2\sin t$. The angle between $F$ and $P$ at time $t$ is

1. ${90}^0$

2. $0^0$

3. ${180}^0$

4. ${30}^0$

Q. A solid cylinder is rolling without slipping on a plane having inclination θ and the coefficient of static friction μ_s. The relation between θ and μ_{s }is 1)†an θ>3μ_s 2)†an θ≤3μ_s 3)†an θ<3μ_s^{

Q. A truck stars from rest and accelerates uniformly with 5m/s^2.The minimum value of coefficient of static friction between surface of truck and a box placed on it such that box does not slip, back

Q. A batsman hits back a ball straight in the direction of the bowlerwithout changing its initial speed of 12 m/s. If the mass of the ball isO.15 kg, determine the impulse imparted to the ball. (Assume linear2.motion of the ball)(B) 3.6 Ns(A)4.6 Ns(D) O Ns(C) 2.6 Ns(E) None of these

Q. A block of mass m_1 resting on a frictionless horizontal surface is connected to a spring of spring cons†an t k that is anchored in a near by wall. A block of mass m_2 is placed on the top of the first block. The coefficient of static friction between the two blocks is μ .Assuming that the two blocks move together as a unit , find the period of oscillation of the system and also find maximum amplitude that permits the two bodies to move as unit.

Q. Consider a cylinder of mass M and radius R lying on a rough horizontal plane. It has a plank of mass m and lenght l at its top most point . A force F is applied on the plank such that the plank moves and causes the cylinder to roll. The plank always remain horizontal .There is no slipping at any point of contact .Calculate the acceleration of cylinder and frictional force at the two contacts

Q.

A body of mass m hangs by an inextensible string that passes over a smooth massless pulley that is fitted with a light spring of stiffness k as shown in the figure, such that the spring is initially at natural length. If the body is released from rest and the spring is released, calculate the maximum elongation of the spring.

1. 

2. 

3. 

4. 

Q. 12. A block of mass m is in contact with the cart. Thecoefficient of static friction between the block andthe cart is . The acceleration a of the cart thatprevent the block from falling will beCONOmg(1) a(2)(3) a(4) a

Q. A truck moving on a smooth horizontal surface with a uniform speed u is carrying stone-dust. If a mass $\Delta m$ of the stone-dust `leaks down’ from the truck in the time $\Delta t$, the force needed to keep the truck moving at its uniform speed is

1. 
2. 
3. 
4. 

Q. 18.In the arrangement shown in figure neglect the masses of the pulley and string and also friction. The accelerations of blocks A and B are A) g , g/2 B) g/2, g C) 3g/2 , 3g/4 D) g, g

Q. determine the maximum acceleration of the truck in which a box lying on the floor of its back will remain stationary given that the coefficient of static friction between the box and trucks floor is 0.2

Q.

Two balls at same temperature collide. What is conserved?

1. Temperature

2. Velocity

3. Kinetic energy

4. Momentum

Q.

A shell is fired from cannon with a velocity V at an angle $\theta$ with the horizontal direction. At the highest point in its path, it explodes into two pieces of equal masses. One of the pieces retraces its path to the cannon. The speed of the other piece immediately after the explosion is

1. 

2. 

3. 

4. 

Q. A block of mass m is kept over another block of mass 2m, Coefficient of friction between two blocks is μ and that of between lower block and the horizontal surface is zero. A horizontal force F=4/3μ mg is applied on the block of mass 2m. Acceleration of lower block is.

Q. a motorcar has a width 1.1m between wheels .its centre of gravity is 0.62m above the ground and the coefficient of friction between the wheels and the road is 1.9. what is the maximum possible speed to avoid overturning of car, if the centre of gravity inscribes a circle of radius 15m?(road surface is horizontal)(g=10m/s^{2

Q. a solod ball of radius 0.2m and mass 1kg is given an ins†an†an eous impulse of 50Ns at a point find the no. ofrotations made by the ball about its diameter before hitting ground the ball is kept on smooth surface initiall

Q.
Which of Newton's Laws gives the reason for why you can feel things that you touch?

1. Third law
2. None of the above
3. Second law
4. First law

Q. A block of mass 2kg is pushed against a rough vertical wall with a force of 40N cofficient of static friction being 0.5. Another horizontal force of 15N is applied on the block in a direction parallel to the wall. Will the block move if yes in which direction?

Q. if momentum of a body increases by 11 percent then what is the chenge its kinetic energ

Q. A solid sphere is at rest on a horizontal surface. A horizontal impulse $J$ is applied at a height $h$ from the centre. The sphere starts rolling just after the application of impulse. The ratio $\frac{h}{R}$ will be

1. $\frac{2}{5}$
2. $\frac{1}{3}$
3. $\frac{3}{5}$
4. $\frac{5}{2}$

Q. A small ball of mass m is kept on a rough inclined surface of inclination theta in an elevator. The elevator goes up with uniform velocity v and the block doesnt slide on the wedge. The work done by the force of friction on the block in time t will be 1) 0 2) mgvt cos^2θ 3) mgvt sin^2θ 4) mgvt sin2

Q.

A body of mass 'M' collides against a wall with a velocity v and retraces its path with the same speed. The change in momentum is (take initial direction of velocity as positive)

1. Zero

2. 2Mv

3. Mv

4. - 2 Mv

Q. A block of mass m rest on a horizontal floor with which it has a coefficient of static friction mue. For the block to just move

Q. A mass of10 kg just pulled along rough horizontal surface when a force of 58.8 N is applied parallel to the surface .then what is the coefficient of static friction between 2 surfaces

Q. A ball is moving with an initial velocity $30\hat{i}\text{m/s}$ towards a wall oriented at an angle such that the velocity of the ball after collision with the wall becomes $-30\hat{j}\text{m/s}$. If mass of the ball is $0.5\text{kg}$, then the magnitude of the impulse imparted by the wall is

1. $0\text{N.s}$
2. $30\text{N.s}$
3. $15\text{N.s}$
4. $15\sqrt{2}\text{N.s}$

Q. 11. In the figure coefficient of friction 8kg block and surface is zero and coefficient of friction between blocks is 0.4. A force of 20 N is applied on 8Kg block as shown. The acceleration of 4kg mass is___

Q. A ball of mass $2\text{kg}$ is dropped from a height of $20\text{m}$. After striking the ground, the ball bounces back with half of its striking speed. Find the impulse imparted by the normal reaction from the ground. Take $g=10{\text{m/s}}^2$.

1. $40\text{N-s}$
2. $80\text{N-s}$
3. $0\text{N-s}$
4. $60\text{N-s}$

Q. Why are shockers used in cars, scooters and motorcycles ?

Q. A ball of mass $2\text{kg}$, travelling with a velocity $2\hat{i}+3\hat{j}+4\hat{k}\text{m/s}$ receives an impulse of $4\hat{i}+2\hat{j}\text{N-s}$. What is the velocity of the ball immediately after the impulse is imparted?

1. $4\hat{i}+4\hat{j}+4\hat{k}\text{m/s}$
2. $2\hat{i}+2\hat{j}+2\hat{k}\text{m/s}$
3. $6\hat{i}+5\hat{j}+4\hat{k}\text{m/s}$
4. $6\hat{i}+5\hat{j}\text{m/s}$

Q.

A block of mass 2kg is placed on the floor. The coefficient static friction is 0.4. A force of friction 2.5N is applied on the block. Calculate the force of friction between the floor and the block.