Laws of motion practice · Mixed difficulty

Two persons of equal weight are hanging by their hands from the ends of a light rope hung over a frictionless pulley. They begin to climb the rope. One person can climb with twice the speed of the other (with respect to the rope). Who will get to the top first?

Which one of the following is not used to reduce friction

Which one of the following is not a force

A bird is sitting in a large closed cage which is placed on a spring balance. It records a weight of 25 N. The bird (mass m=0.5 kg) files upward in the cage with an acceleration of $2\;m/{s^2}$. The spring balance will now record a weight of

A lift is moving upwards with a uniform velocity v in which a block of mass m is lying. The frictional force offered by the block, when coefficient of the frictional is $\mu$, will be

Assertion : The two bodies of masses M and m (M > m) are allowed to fall from the same height if the air resistance for each be the same then both the bodies will reach the earth simultaneously.
Reason : For same air resistance, acceleration of both the bodies will be same.

A box is placed on an inclined plane and has to be pushed down. The angle of inclination is

When two surfaces are coated with a lubricant, then they

An automobile travelling with a speed of 60 km/h, can brake to stop within a distance of 20 m. If the car is going twice at fast,i.e. 120 km/h, the stopping distance will be

Two bodies having masses ${m_1}\,and\,{m_2}$ and velocities ${\mathrm{\vec u}_1}\,and\,{\mathrm{\vec u}_2}$ collide and form a composite system of ${m_1}{\mathrm{\vec v}_1} + {m_2}{\mathrm{\vec v}_2} = 0\left( {{m_1} \ne {m_2}} \right)$. The velocity of the composite system is

Motion of the particle is non uniform when

It is difficult to move a cycle with brakes on because

The resultant force of 5N and 10 N cannot be

A car is moving along a straight horizontal road with a speed ${v_0}$. If the coefficient of friction between the tyres and the road is $\mu$, the shortest distance in which the car can be stopped is

If the coefficient of friction is $\frac{1}{{\sqrt 3 }}$ the angle of friction is

A body of mass 2 kg lying on ice with given a velocity of 5m/s is stopped by friction is 4 sec. Find the coefficient of friction between block and ice $\left( {g = 10\,m/{s^2}} \right)$

A gun fires N bullets per second, each of mass m with velocity v. The force exerted by the bullets on the gun is

A constant force acts on a body of mass 0.9 kg at rest for 10s. If the body moves a distance of 250 m, the magnitude of the force is

The coefficient of limiting friction $\mu$ is defined as

In which of the following cases, net force acting on the
body is zero?

Newton's second and third laws of motion lead to the conservation of

A 10 kg stone is suspended with a rope of breaking strength 30 kg wt. The minimum time in which the stone can be raised through a height 10 m starting from rest is ( taking $g = 10\;N/kg)$

A body possesses kinetic energy x, moving on a rough horizontal surface, is stopped in a distance y. The friction force exerted on the body is

If two masses (M & m) are connected on a horizontal plane and a force is applied on the combination, then the tension T depends on

Which of the following statements is not true

Assertion: During head on collision between two bodies let $\Delta p_1$ is change in momentum of first body and $\Delta p_2$ the change in momentum of the other body, then $\Delta p_1=\Delta p_2$.

Reason: Total momentum of the system should remain constant.

The coefficient of static friction between two surfaces depends upon

Inertia is the property of a body linked to tendency of a body

Inertia of an object is directly dependent on

A particle rests on the top of a hemisphere of radius R. Find the smallest horizontal velocity that must be imparted to the particle if it is to leave the hemisphere without sliding down it