Normal Force

Q.

When a car moves on a banked road, the centripetal force is due to

1. vertical component of the normal force and the frictional force

2. frictional force

3. horizontal component of the normal force

4. horizontal component of the normal force and the frictional force

Q. 26. A wooden stick of length L radius R and density d has a small metal piece of mass m ( of negligble volume) attached to one of its end. Find the minimum value for mass m ( in terms of the parameters given) that would make the stick float vertically in equilibrium in a liquid of density D( greater than d)

Q. block A of mass 4 kg is to be kept at rest against a smooth vertical wall by applying a force . the required force is

Q. A vehicle of mass m is moving on a rough horizontal road with momentum P.if the coefficient of friction between the tyres and the road be mu, then the stopping distance is ?

Q. A block of mass m is given a velocity V on long plank of mass M kept on a smooth horizontal surface .the friction Coefficient between the block and plank is mu. find the work done by friction on the system (block + plank )till the instant when relative velocity of block with respect to plank becomes V/2 .

Q. A body is subjected to a constant force given by F(N)  iˆ  2ˆj  3kˆ  . What is the work done by this force in moving the body through a distance of 4 m along the z-axis and then 3 m along the y-axis? (1) 18 J (2) 12 J (3) 16 J (4) Zero

Q. 81.If 500 sound waves are produced in 1 minute, what is time taken by a vibrating particle to move from its mean position to the immediate rarefaction?

Q.

The component of contact force normal to the surfaces in contact is called

1. Normal reaction

2. Tension

3. Gravitational component

4. Friction

Q. A particle of mass m moves in a certain plane P due to a force F whose magnitude is constant and whose vector rotates in that plane with a constant angular velocity w(omega). Assuming the particle to be stationary at the moment t=0, find its velocity as a function of time and the distance covered by the particle between two successive stops.

Q.

An object is suspended from a spring balance in a lift. The reading is 240 N when the lift is at rest. If the spring balance reading now changes to 220 N, then the lift is moving

1. Downward with constant speed

2. Upward with increasing speed

3. Downward with decreasing speed

4. Downward with increasing speed

Q.

A smooth block of mass m is placed on a smooth plank of mass M. The acceleration of M when it is acted by a force F is? Also find acceleration of m?

1. 

2. 

3. 

4. 

Q. A block of mass 5 kg is at rest on a rough inclined surface. If angle of inclination of plane is 60^°, then force appliedby it on block is(1) 50 N(3) 25N(2) 25\sqrt3N(4) 50\sqrt3N

Q.

Two forces with equal magnitudes F act on a body and the magnitude of the resultant force is F/3. The angle between the two forces is

1. 

2. 

3. 

4. 

Q. ntn ntQ. A tube of length L is filled completely with an incompressible liquid of mass M & closed at both the ends. The tube is then rotated in a horizontal plane about one of its ends with a uniform angular velocity . The force exerted by the liquid at the other end isn nt1) ML22/2n nt2) ML2/2n nt3) ML2/2n nt4) ML2n

Q. a body of mass m lies at rest rough surface.the frictional force i

Q. A boy pulls a toy car with a force of 5 N by a string which makes an angle of 30^° with thehorizontal, in order to move the toy by the distance of 2m in horizontal direction. If the string were inclined at an angle of 60^° with horizontal, how much pull would be applied along the string to move it through the same distance of 2 m. (A) 6.12N (B) 8.6 N (C) None of these (D) 5 N (E) 3.5 N

Q. 36. Four equal mass of bodies are kept four corners of the square, then find force on one of mass due to other three?

Q. A small block slides without friction down an inclined plane starting from rest. Let S_n be the dis†an ce travelled from t=n-1 to t=n. Then, S_n/S_{n+1} is (1) 2n-1/2n (2) 2n+1/2n-1 (3) 2n-1/2n+1 (4) 2n/2n+1

Q. why internal force does not affect the position of center of mass of any object?

Q.

A smooth block of mass m is placed on a smooth plank of mass M. The acceleration of M when it is acted by a force F is? Also find acceleration of m?

1. $a_M=\frac{F}{M+m};a_m=\frac{F}{M+m}$

2. $a_M=\frac{F}{M+m};a_m=zero$

3. $a_M=zero;a_m=zero$

4. $a_M=\frac{F}{M};a_m=zero$

Q. a block of mass m placed on a rough inclined plane and the block is at rest on the inclined plane . find tge force exerted by tge inclined plane on tge block

Q. An elevator is accelerating upwards with an acceleration of $6{\text{m/s}}^2$. Inside it a person of mass $50\text{kg}$ is standing on a weighing machine having rough surface which is kept on an inclined plane having angle of inclination ${60}^{\circ }$. The reading of the weighing machine is -
$($Take $g=10{\text{m/s}}^2)$

1. $50\text{kg}$
2. $80\text{kg}$
3. $40\text{kg}$
4. $60\text{kg}$

Q. Two bodies A and B of masses 5 kg and 10 kg in contact with each other rest on a table against a rigid wall (Fig. 5.21). The coefficient of friction between the bodies and the table is 0.15. A force of 200 N is applied horizontally to A. What are (a) the reaction of the partition (b) the action-reaction forces between A and B ? What happens when the wall is removed? Does the answer to (b) change, when the bodies are in motion? Ignore the difference between μs and μk.

Q. 34. A car weights 1800 kg. The distance between its front and back axles is 1.8 m. Its centre of gravity is 1.05 m behind the front axle. Determine the force exerted by the level ground on each front wheel and back wheel.

Q. A block of mass m is placed on a smooth wedge of inclination θ .The whole system is accelerated horizontally so that the block does not slip on the wedge .The force exerted by the wedge on the block has a magnitude

Q.

A person is sliding an iron box across the floor. Its free body diagram will be

1. 

2. 

3. 

4. 

Q. Normal force is a reaction due to electromagnetic forces.

1. True
2. False

Q. If block A of mass 5 kg is placed over block B of mass 5 kg .All surfaces are smooth .A force 10 N is applied on B horizontally .Find the acceleration of A?

Q. A small block slides , without friction, down an inclined plane starting from rest .Let Sn be the distance travelled from t=(n-1) to t=n. Then Sn/Sn+1is

Q. Water from a tap emerges vertically downwards with an initial speed of $1\text{m/s}$. If the cross-sectional area of tap is ${10}^{-4}{\text{m}}^2$ then find the cross sectional area of stream $0.15\text{m}$ below the tap.

1. $5\times {10}^{-4}{\text{m}}^2$
2. $2\times {10}^{-5}{\text{m}}^2$
3. $5\times {10}^{-5}{\text{m}}^2$
4. $1\times {10}^{-4}{\text{m}}^2$