A ball of weight 0.1 kg coming with speed 30 m/s strikes with a bat and returns in opposite direction with speed 40 m/s, then the impulse is (Taking final velocity as positive) 

(1) $-0.1\times \left(40\right)-0.1\times \left(30\right)$

(2) $0.1\times \left(40\right)-0.1\times (-30)$

(3) $0.1\times \left(40\right)+0.1\times (-30)$

(4) $0.1\times \left(40\right)-0.1\times \left(20\right)$

A ball of mass m falls vertically to the ground from a height h₁ and rebound to a height h₂. The change in momentum of the ball on striking the ground is 

(1) $mg(h_1-h_2)$

(2) $m\left(\sqrt{2g{h}_1}+\sqrt{2g{h}_2}\right)$

(3) $m\sqrt{2g(h_1+h_2)}$

(4) $m\sqrt{2g}(h_1+h_2)$

Consider the following two statements

1. Linear momentum of a system of particles is zero

2. Kinetic energy of a system of particles is zero Then 

(1) 1 implies 2 and 2 implies 1

(2) 1 does not imply 2 and 2 does not imply 1

(3) 1 implies 2 but 2 does not imply 1

(4) 1 does not imply 2 but 2 implies 1

A force-time graph for a linear motion is shown in figure where the segments are circular. The linear momentum gained between zero and 8 second is 

1. $-2\pi newton\times second$

2. $Zeronewton\times second$

3. $+4\pi newton\times second$

4. $-6\pi newton\times second$

A particle of mass m moving with a velocity u makes an elastic one dimensional collision with a stationary particle of mass m establishing a contact with it for extremely small time T. Their force of contact increases from zero to F₀ linearly in time $\frac{T}{4}$, remains constant for a further time $\frac{T}{2}$ and decreases linearly from F₀ to zero in further time $\frac{T}{4}$ as shown. The magnitude possessed by F₀ is

(1) $\frac{mu}{T}$

(2) $\frac{2mu}{T}$

(2) $\frac{4mu}{3T}$

(4) $\frac{3mu}{4T}$

Two blocks A and B of masses 3m and m respectively are connected by a massless and inextenisible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of A and B  immediately after the string is cut, are respectively 

1. $g,\frac{g}{3}$

2. $\frac{g}{3},g$

3. $g,g$

4. $\frac{g}{3},\frac{g}{3}$

One end of the string of length \(l\) is connected to a particle of mass \(m\) and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in a circle with speed \(v\), the net force on the particle (directed towards the centre) will be: (\(T\) represents the tension in the string)

A rigid ball of mass m strikes a rigid wall at ${60}^{°}$ and gets reflected without loss of speed as shown in the figure. The value of impulse imparted by the wall on the ball will be 

(1) mv

(2) 2mv

(3) mv/2

(4) mv/3

A car is negotiating a curved road of radius R. The road is banked at angle $\mathrm{\theta }$. The coefficient of friction between the tyres of the car and the road is ${\mathrm{\mu }}_{\mathrm{s}}$. The maximum safe velocity on this road is

1. $\sqrt{\mathrm{gR}\left(\frac{{\mathrm{\mu }}_{\mathrm{s}}+\mathrm{tan\theta }}{1-{\mathrm{\mu }}_{\mathrm{s}}\mathrm{tan\theta }}\right)}$

2. $\sqrt{\frac{\mathrm{g}}{\mathrm{R}}\left(\frac{{\mathrm{\mu }}_{\mathrm{s}}+\mathrm{tan\theta }}{1-{\mathrm{\mu }}_{\mathrm{s}}\mathrm{tan\theta }}\right)}$

3. $\sqrt{\frac{\mathrm{g}}{{\mathrm{R}}^2}\left(\frac{{\mathrm{\mu }}_{\mathrm{s}}+\mathrm{tan\theta }}{1-{\mathrm{\mu }}_{\mathrm{s}}\mathrm{tan\theta }}\right)}$

4. $\sqrt{{\mathrm{gR}}^2\left(\frac{{\mathrm{\mu }}_{\mathrm{s}}+\mathrm{tan\theta }}{1-{\mathrm{\mu }}_{\mathrm{s}}\mathrm{tan\theta }}\right)}$

Three blocks A, B and C of masses 4 kg, 2 kg and 1 kg respectively, are in contact on a frictionless surface, as shown. If a force of 14 N is applied on the 4 kg block, then the contact force between A and B is


1.2N

2. 6N

3. 8N

4. 18N