Archives

Force of 5 N acts on a body of weight 9.8 N. what is the acceleration produced in ms^–2

1) 49.00 2) 5.00 3) 1.46 4) 0.51 Answer: 2) 5.00 Solution: W = mg 9.8 = m x 9.8 m = 1 Kg Force, F = ma----(1) 5 = 1 x a a = 5 m/s2... View Article

A lump of clay of mass 10g travelling with a velocity 10cm/sec, towards east collides head on with another lump of clay of mass 10g travelling with velocity of 20 cm/sec towards west. If the two lumps coalesce after collision, what is its velocity if no external force acts on the system?

1) 15 cm/ sec towards west 2) 15 cm/sec towards east 3) 5 cm/sec towards west. 4) 5 cm/sec towards east. Answer: 4) 5 cm/sec towards east.... View Article

The velocity of a body of mass 20 kg decreases from 20ms^–1 to 5ms^–1 in a distance of 100 m. Force on the body is

1) –27.5 N 2) –47.5 N 3) –37.5 N 4) –67.5 N Answer: 3) –37.5 N Solution: F = m x a v2 = u2 + 2as Hence, a =... View Article

A constant force acts on a body of mass m at rest. The velocity V acquired in traversing a specific distance depends on m as

1) V ∝ 1/m 2) v ∝ 1/√m 3) v ∝ m 4) v ∝ √m Answer: 2) v ∝ 1/√m Solution: By Newton's... View Article

A body of mass 60 kg is dragged with just enough force to start moving on a rough surface with coefficients of static and kinetic frictions 0.5 and 0.4 respectively. On applying the same force, what is the acceleration?

1) 0.98 m/s2 2) 9.8 m/s2 3) 0.54 m/s2 4) 5.292 m/s2 Answer: 1) 0.98 m/s2 Solution: Static friction, fs = μsR fk= μkR When... View Article

A container, filled with water and having a wooden block floating in it, is allowed to fall freely under gravity. During the fall, the upthrust on the wooden block will be

1) equal to the weight of block in air 2) equal to weight of water displaced by the portion of the block 3) equal to loss of weight of the... View Article

In a tug of war, two opposite teams are pulling the rope with an equal and opposite force of 10 KN at each and of the rope, so that condition of equilibrium exists. What is the tension in the rope?

1) Zero 2) 5 KN 3) 10 KN 4) 20 KN Answer: 3) 10 KN Solution: In tug of war between two teams, if equilibrium exists, then... View Article

If E, G and N represent the magnitudes of electromagnetic, gravitational and nuclear forces between two protons at a given separation, then,

1) N = E = G 2) E < N < G 3) N > G < E 4) E > G > N Answer: 4) E > G > N Solution: When protons are at a given... View Article

A bullet is fired by a light rifle and the other with a heavy rifle by the same force. Which rifle will cause more injury to the shoulder

1) Light rifle 2) Heavy rifle 3) Both will cause the same injury 4) The information is insufficient Answer: 1) Light rifle Solution:... View Article

A spring is compressed between two toy carts of masses m₁ and m₂. When the toy carts are released, then spring exerts on each, equal and opposite average force for the same time t. Assume that there is no friction between the toy carts and the ground, then the speeds of toy carts are:

1) in opposite directions but in inverse ratio of masses 2) in the opposite directions but in the direct ratio of masses 3) equal but in... View Article

A 5000 kg rocket is set for vertical firing. The exhaust speed is 800 ms^-1. To give an initial upward acceleration of 20 ms^-2, the amount of gas ejected per second to supply the needed thrust will be (take,g =10 ms^-2 )

1) 127.5 kgs-1 2) 187.5 kgs-1 3) 185.5 kgs-1 4) 137.5 kgs-1 Answer: 3) 185.5 kgs-1 Solution: Thurst force, Ft = vr (-dm/dt) Net force... View Article

A block rests on a rough inclined plane making an angle of 30° with the horizontal. The coefficient of static friction between the block and the plane is 0.8. If the frictional force on the block is 10 N, the mass of the block (in kg) is (take, g =10 ms^-2)

1) 2.0 2) 4.0 3) 1.6 4) 2.5 Answer: 1) 2.0 Solution: The frictional force on the block, fs = mgsinθ (for body at rest) ⇒ m x 10 x... View Article

The force required to move a mass of 1 kg at rest on a horizontal rough plane (µ = 0.1 and g = 9.8 ms^-2) is

1) 0.98 N 2) 0.49 N 3) 9.8 N 4) 4.9 N Answer: 1) 0.98 NSolution: F = fr = μN = μmg = 0.1 x 1 x 9.8 = 0.98 N... View Article

A coin of mass 10 g is placed over a book of length 50 cm. The coin is on the verge of sliding when one end of the book is lifted 10 cm up. The coefficient of static friction between the book and the coin is

1) 1.0 2) 0.4 3) 0.3 4) 0.2 Answer: 4) 0.2 Solution: Mass of the coin = 10 g Length of the book = 50 cm Height = 10 cm Using the... View Article

A marble block of mass 2 kg lying on ice when given a velocity of 6 m/s is stopped by friction in 10 s. Then, the coefficient of friction is

1) 0.02 2) 0.03 3) 0.06 4) 0.01 Answer: 3) 0.06 Solution: Given, Mass of marble bock = 2 Kg Velocity, v = 6 ms-1 Friction = 10... View Article

The engine of a car produces an acceleration of 6ms^-2 in the car. If this car pulls another car of the same mass, then the acceleration would be

1) 6 ms-2 2) 12 ms-2 3) 3 ms-2 4) 1.5 ms-2 Answer: 3) 3 ms-2 Solution: Given, a = 6ms-2 Force, F = ma For the same... View Article

M	T	W	T	F	S	S
		1	2	3	4	5
6	7	8	9	10	11	12
13	14	15	16	17	18	19
20	21	22	23	24	25	26
27	28	29	30