Laws of Motion · Physics · WB JEE
MCQ (Single Correct Answer)
A shell of mass 10 kg is moving with a velocity of 10 ms$$-$$1 when it blasts and forms two parts of mass 9 kg and 1 kg respectively. If the 1st mass is stationary, the velocity of the 2nd is
Force required to move a mass of 1 kg at rest on a horizontal rough plane ($$\mu$$ = 0.1 and g = 9.8 m/s2) is
A rocket of mass 100 kg burns 0.1 kg of fuel per sec. If the velocity of exhaust gas is 1 km/sec, then it lifts with an acceleration of
A bullet emerges from a barrel of length 1.2 m with a speed of 640 ms$$-$$1. Assuming constant acceleration, the approximate time that it spends in the barrel after the gun is fired is
What force $$\mathrm{F}$$ is required to start moving this $$10 \mathrm{~kg}$$ block shown in the figure if it acts at an angle of $$60^{\circ}$$ as shown? $$(\mu_s=0.6)$$
A body of mass 2 kg moves in a horizontal circular path of radius 5 m. At an instant, its speed is 2$$\sqrt5$$ m/s and is increasing at the rate of 3 m/s$$^2$$. The magnitude of force acting on the body at that instant is,
If a string, suspended from the ceiling is given a downward force F1, its length becomes L1. Its length is L2, if the downward force is F2. What is its actual length?
A golf ball of mass 50 gm placed on a tee, is struck by a golf-club. The speed of the golf ball as it leaves the tee is 100 m/s, the time of contact on the ball is 0.02 s. If the force decreases to zero linearly with time, then the force at the beginning of the contact is
Three blocks are pushed with a force F across a frictionless table as shown in figure above. Let N1 be the contact force between the left two blocks and N2 be the contact force between the right two blocks. Then,