Impulse & Momentum Conservation

A cricket ball of mass $120$ g is moving with a velocity of $8$ m/s and is hit by a bat so that the ball gets turned back with a velocity of $12$ m/s. If the duration of contact between the ball and bat is $0.02$ s, the impulse (in Ns) given to the ball by the bat is

$100$ balls each of mass $m$ moving with speed $v$ simultaneously strike a wall normally and reflected back with same speed, in time $t$ s. The total magnitude of force exerted by the balls on the wall is

A machine gun fires a bullet of mass 40g with a speed of $600$ ms$^{-1}$. The person holding the gun can bare maximum force of 168N on it. The number of bullets that can be fired from the gun per second is

A bullet is fired from a gun. The force on the bullet is $F = (600 - 2 \times 10^{5} t)$ N where $t$ is in second. The force on the bullet becomes zero as soon as it leaves the barrel. The average impulse imparted to the bullet is

A machine gun fires a bullet of mass 35 gram with a speed of $600\text{ m/s}$. The person holding the gun can extract a maximum force of 147 N on it. The number of bullets that can be fired from the gun per second is

A conveyor belt is moving with constant velocity (V). Sand is being dropped on the belt at the rate of $M\text{ kg/s}$. The force necessary to keep the belt moving with a constant velocity $V\text{ m/s}$ will be

A ball is dropped on the floor from a height of 20 m. It rebounds to a height of 5 m. Ball remains in contact with floor for 1 s. The average acceleration during contact is (acceleration due to gravity $= 10\text{ m/s}^{2}$)

Force is applied to a body of mass 3 kg at rest on a frictionless horizontal surface as shown in the force against time (F-t) graph. The speed of the body after 1 s is

A player caught a cricket ball of mass $150\text{ g}$ moving at a speed of $20\text{ m/s}$. If the catching process is completed in $0.1\text{ s}$, the magnitude of force exerted by the ball on the hand of the player is:

A cricket player catches a ball of mass $120\text{ g}$ moving with $25\text{ m/s}$ speed. If the catching process is completed in $0.1\text{ s}$ then the magnitude of force exerted by the ball on the hand of player will be (in SI unit):

Figures (a), (b), (c) and (d) show variation of force with time.

The impulse is highest in figure.

A machine gun fires bullets of mass $30\text{ g}$ with velocity of $1000\text{ m/s}$. The man holding the gun can exert a maximum force of $300\text{ N}$ on it. How many bullets can he fire per second at most?

A football player is moving southward and suddenly turns eastward with the same speed to avoid an opponent. The force that acts on the player while turning is:

A bullet of mass $10$ gram is fired with velocity of $100\text{ m/s}$ from the gun of mass $1\text{ kg}$. Recoil speed of the gun is:

A particle of mass M originally at rest is subjected to a force whose direction is constant but magnitude varies with time according to the relation

$F = F_0\left[1 - \left(\frac{t-T}{T}\right)^{2}\right]$

Where F0 and T are constants. The force acts only for the time interval 2T. The velocity v of the particle after time 2T is:

Water is flowing at a speed of 1.5 ms${}^{-1}$ through a horizontal tube of cross-sectional area 10$-$2 m2 and you are trying to stop the flow by your palm. Assuming that the water stops immediately after hitting the palm, the minimum force that you must exert should be (density of water = 103 kgm${}^{-3}$).

A body of mass M hits normally a rigid wall with velocity V and bounces back with the same velocity. The impulse experienced by the body is

Sand is being dropped on a conveyer belt at the rate of M kg/s. The force necessary to keep the belt moving with a constant velocity of $v$ m/s will be:

A rocket with a lift-off mass $3.5 \times 10^{4}\text{ kg}$ is blasted upwards with an initial acceleration of $10\text{ m/s}^{2}$ Then the initial thrust of the blast is

A cricketer catches a ball of mass 150 gm in 0.1 sec moving with speed 20 m/s, then he experiences force of

A 1 kg stationary bomb is exploded in three parts having mass 1: 1: 3 respectively. Parts having same mass move in perpendicular direction with velocity 30 m/s, then the velocity of bigger part will be

A body of mass 3 kg hits a wall at an angle of 60° and returns at the same angle. The impact time was 0.2 sec. The force exerted on the wall

The force on a rocket moving with a velocity $300\text{ m/s}$ is $210\text{ N}$. The rate of consumption of fuel of rocket is

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

A man fires a bullet of mass $200\text{ gm}$ at a speed of $5\text{ m/s}$. The gun is of one kg mass. By what velocity the gun rebounds backward?

In a rocket, fuel burns at the rate of $1\text{ kg/s}$. This fuel is ejected from the rocket with a velocity of $60\text{ km/s}$. This exerts a force on the rocket equal to

A satellite in force free space sweeps stationary interplanetary dust at a rate of $dM/dt = \alpha v$, where $M$ is mass and $v$ is the speed of satellite and $\alpha$ is a constant. The acceleration of satellite is

A $600\text{ kg}$ rocket is set for a vertical fring. If the exhaust speed is $1000\text{ m s}^{-1}$, the mass of the gas ejected per second to supply the thrust needed to overcome the weight of rocket is

A body of mass $5\text{ kg}$ explodes at rest into three fragments with masses in the ratio $1:1:3$. The fragments with equal masses fly in mutually perpendicular directions with speeds of $21\text{ m/s}$. The velocity of heaviest fragment in m/s will be