HARD
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A bucket with massm2 and a block with mass m1 are hung on a pulley system. Find the magnitude of the acceleration with which the bucket and the block are moving and the magnitude of the tension force T by which the rope is stressed. Ignore the masses of the pulley system and the rope. The bucket moves up and the block moves down.

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Important Questions on Newton's Laws of Motion

EASY
A person jumps from the 5th  storey of a building with load on his head. The weight experienced by him before reaching the earth will be
HARD

Two weights of the mass m1 and m2>m1 are joined by an inextensible string of negligible mass passing over a fixed frictionless pulley. The magnitude of the acceleration of the loads is

EASY
A box filled with water has a small hole on its side near the bottom. It is dropped from the top of a tower. As it falls, a camera attached on the side of the box records the shape of the water stream coming out of the hole. The resulting video will show
 
MEDIUM
A block of mass m is placed on a smooth inclined wedge ABC of inclination θ as shown in the figure. The wedge is given an acceleration a towards the right. The relation between a and θ for the block to remain stationary on the wedge is

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MEDIUM
An object takes n times as much time to slide down a 45° rough inclined plane as it takes to slide down a perfectly smooth 45° inclined plane. The coefficient of kinetic friction between the rough plane and the object is
EASY
A stone is dropped from the top of a building. When it crosses a point 5 m below the top, another stone starts to fall from a point 25 m below the top. Both stones reach the bottom of building simultaneously. The height of the building is :
EASY
A body is projected vertically upwards with a velocity 'u' from the top of a tower. Time taken by it to reach the ground is 'n' times the time taken by it to reach the highest point in its path. Height of the tower is
MEDIUM

An inclined plane making an angle of 30° with the horizontal is placed in a uniform horizontal electric field 200NC as shown in the figure. A body of mass 1 kg and charge 5 mC is allowed to slide down from rest at a height of 1 m. If the coefficient of friction is 0.2, find the time taken by the body to reach the bottom.
g=9.8 m s-2; sin30°=12; cos30°=32

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MEDIUM
Two blocks of masses m1 and m2 are suspended by a massless string passing over a smooth pulley. If the acceleration of the system is g8,then the ratio of the masses m2 m1=
MEDIUM

Two blocks A and B of masses 1.5 kg and 0.5 kg respectively are connected by a massless inextensible string passing over a frictionless pulley as shown in the figure. Block A is lifted until block B touches the ground and then block A is released. The initial height of block A is 80 cm when block B just touches the ground. The maximum height reached by block B from the ground after the block A falls on the ground is

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EASY
On a smooth plane surface (figure) two block A and B are accelerated rightwards by applying a force 15 N on A. If mass of B is twice that of A, the force on B is

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MEDIUM
A ball is thrown vertically downward with a velocity of 20 m s-1 from the top of a tower. It hits the ground after some time with a velocity of 80 m s-1. The height of the tower is: g=10 m s-2
EASY
A block of mass 48 kg kept on a smooth horizontal surface is pulled by a rope of length 4 m by a horizontal force of 25 N applied to the other end. If the linear density of the rope is 0.5 kg m-1, the force acting on the block is
HARD

A student skates up a ramp that makes an angle 30° with the horizontal. He/she starts (as shown in the figure) at the bottom of the ramp with speed v0 and wants to turn around over a semicircular path xyz of radius R during which he/she reaches a maximum height h (at point y) from the ground as shown in the figure. Assume that the energy loss is negligible and the force required for this turn at the highest point is provided by his/her weight only. Then (g is the acceleration due to gravity)

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EASY
Two bodies of mass 4 kg and 6 kg are tied to the ends of a massless string. The string passes over a pulley which is frictionless (see figure). The acceleration of the system in terms of acceleration due to gravity g is:
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HARD
Deduce the relation between the acceleration of the load and effort  in a movable pulley system. 
HARD

A crate of mass 20 kg is pulled vertically upwards using a rope that passes over a first pulley, under a second pulley and over a third pulley. At the other end of the rope there is a ball of mass 30 kg. Each pulley has mass m kg. The first and third pulleys are fixed at the same horizontal level and are 4 m apart. The second pulley is an equal distance from the first and third pulleys and hangs at a distance 2 m below them. It is not fixed, but it does not move.

What modelling assumptions need to be made? Which of these assumptions is unlikely to affect the equilibrium of the second pulley?

MEDIUM
What is a movable pulley system? Mention its advantage and disadvantage.
MEDIUM

Represent the union of two sets by Venn diagram for each of the following.

X={x | x is a prime number between 80 and 100}

Y={y | y is an odd number between 90 and 100}

MEDIUM
Two smooth pulleys are fixed at the same horizontal level. A light inextensible rope passes over the pulleys and a box of mass m kg hangs at each end of the rope. A third box of mass km kg is attached to the midpoint of the rope and hangs between the pulleys so that all three boxes are at the same horizontal level. The portions of the string that are not vertical make an angle of 30° with the horizontal. The system hangs in equilibrium. Find the value of k.