EASY
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A block of mass m is lying at rest on an inclined plane having angle of inclination explain the equilibrium of the block by showing various forces acting on it.

Important Questions on Laws of Motion

MEDIUM

A block of mass 5 kg is kept against an accelerating wedge with a wedge angle of 45° to the horizontal. The co-efficient of friction between the block and the wedge is μ=0.4. What is the minimum absolute value of the acceleration of the wedge to keep the block steady. Assume g=10 m s-2

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EASY
A block is released from rest on a 45° smooth incline and slide a distance d. The time taken to slide the same distance is n times as much to slide on a 45° rough incline than on the smooth incline. The coefficients of friction for the rough incline is
MEDIUM
A block of mass 10 kg is kept on a rough inclined plane as shown in the figure. A force of 3 N is applied on the block. The coefficient of static friction between the plane and the block is 0.6. What should be the minimum value of force P, such that the block does not move downward? (take g=10 m s-2)
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MEDIUM
A plank with a box on it at one end is gradually raised about the other end. As the angle of inclination with the horizontal reaches 30°, the box starts to slip and slides 4.0 m down the plank in 4.0 s. The coefficients of static and kinetic friction between the box and the plank will be, respectively:
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HARD
A ball of mass m kg is rolled up a slope at an angle θ to the horizontal, where sinθ=25. The ball passes a point A with speed 7 m s-1. A point B is 5 m further up the slope than point A. Find the time between passing $B$ on the way up and returning to B on the way down.
HARD
Particles A and B, of masses 0.5 kg and 2.5 kg, respectively, are attached to the ends of a light inextensible string. Particle A is held on a rough slope. The slope is inclined at 30° to the horizontal and the coefficient of friction between the slope and particle A is 0.3. The string passes over a small smooth pulley at the top of the slope and particle B hangs vertically below the pulley. The length of the slope is 4 m and the length of the string is 3 m. Particle B is 1 m above the ground. Particle A is released and moves up the slope. When particle B reaches the ground the string is cut. Show that particle A does not reach the pulley.
HARD
A windsurfer and his board have a total mass of 80 kg. They are being pushed by the water with a force of 20 N westwards. The wind is pushing them northwards with a force F. The windsurfer accelerates on a bearing of 340°. Find the force F and the acceleration of the windsurfer.
HARD

A log of mass 200 kg is dragged up a slope at an angle of 13° to the horizontal by a rope attached to a truck. The rope is at an angle of 20° above the slope.

Draw the force diagram for this situation.

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}

HARD
A block is gently placed at the top of an inclined plane 640 cm long. Find the time taken by the block to slide down to the bottom of the plane. Given that angle of inclination of the plane is 30,μk=0.2 and g=9.8 ms-1
HARD

A ball of mass 3 kg is rolled with initial speed 4 m s-1 up a slope at an angle 10° to the horizontal.

Find the maximum distance up the slope the ball reaches.

HARD

A 10 m long slope makes an angle 30° with the horizontal. A box of mass 8 kg is pulled up the slope by a rope that is parallel to the slope. The coefficient of friction between the box and the slope is 112. At the top of the slope, the rope passes over a smooth pulley. A ball of mass 12 kg hangs from the other end of the rope. The ball is initially 2 m above the ground. The system is released from rest.

Find how long it will take for the box to travel 1.5 m up the slope.

HARD
A cyclist of mass 70 kg (including her bicycle) arrives at an uphill stretch of road of length 30 m with an angle 9° to the horizontal, travelling at 10 m s-1. She exerts a force of 15 N parallel to the slope and there is wind resistance of 5 N against her. Find the time taken to reach the top of the slope.
HARD

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A block of mass 60 kg is pulled up a hill in the line of greatest slope by a force of magnitude 50 N acting at an angle α° above the hill. The block passes through points A and B with speeds 8.5 m s-1 and 3.5 m s-1 respectively (see diagram). The distance AB is 250 m and B is 17.5 m above the level of A. The resistance to motion of the block is 6 N. Find the value of α.

EASY
A block of mass m is placed on a smooth inclined plane of inclination θ with the horizontal. The force exerted by the plane on the block has a magnitude
HARD
A car of mass 1200 kg arrives at a steep upwards slope of length 130 m at 34° to the horizontal. It is travelling at 12 m s-1 and there is air resistance of 100 N. Find the minimum force, assumed constant, the engine must provide for the car to reach the top of the slope.
HARD
A car tows a caravan down a hill. The slope of the hill makes an angle θ with the horizontal, where sinθ=0.05. The force from the car's engine is a braking force (a negative driving force). The car has mass 1800 kg and the caravan has mass 600 kg. The resistance on the car is 20 N and that on the caravan is 80 N. The force in the tow-bar is a thrust of 50 N. Show that the force from the car's engine is -420 N. Take g=10 m s-2.
HARD

Particles A and B, each of mass 0.5 kg, are attached to the ends of a light inextensible string. Particle A is held on a smooth slope inclined at 30° to the horizontal. The string passes over a small smooth pulley at the top of the slope and particle B hangs vertically below the pulley. Particle A is released and moves up the slope.Particle Bhits the ground after 1.2 s It then stays on the ground and particle A travels further up the slope. Particle A does not reach the pulley in the subsequent motion.

Find the acceleration of particle A up the slope. 

HARD

Particles A and B, each of mass 0.5 kg, are attached to the ends of a light inextensible string. Particle A is held on a smooth slope inclined at 30° to the horizontal. The string passes over a small smooth pulley at the top of the slope and particle B hangs vertically below the pulley. Particle A is released and moves up the slope.Particle  B hits the ground after1.2 s  It then stays on the ground and the particle A travels further up the slope. Particle A does not reach the pulley in the subsequent motion.

Find the distance travelled by particle A, from when it is released to when it comes to instantaneous rest.

MEDIUM

A ball of mass 3 kg is rolled with initial speed 4 m s-1 up a slope at an angle 10° to the horizontal.

What assumptions have been made to answer the question?