NCERT Solutions for Chapter: Laws of Motion, Exercise 2: MCQ-II

 The motion of a particle of mass $m$ is given by $x=0$ for $t<0 s, x\left(t\right)=A \sin 4\mathrm{\pi t}$ for $0<t<\left(\frac{1}{4}\right) \mathrm{s}.(\mathrm{A}>0)$ and $x=0$ for $t>\left(\frac{1}{4}\right) \mathrm{s}$. Which of the following statements is true?

In the given figure, the coefficient of friction between the noor and the body $B$ is $0.1$. The coefficient of friction between bodies $\mathrm{B}$ and $\mathrm{A}$ is $0.2$. A force $\mathrm{F}$ is applied as shown on $B$. the mass of $A$ is $\mathrm{m}/2$ and of $\mathrm{B}$ is $\mathrm{m}$. Which of the following statements are true?

 Mass $m_1$ moves on a slope making an angle $\theta$ with the horizontal and is attached to mass ${\mathrm{m}}_2$ by a string passing over a frictionless pulley as shown in the figure. The co-efficient of friction between $m_1$and the sloping surface is $\mu$. Which of the following statements are true?

In given figure, a body $A$ of mass $m$slides on a plane inclined at an angle ${\theta }_1$ to the horizontal and ${\mu }_1$ is the coefficient of friction between $A$and the plane. A is connected by a light string passing over a frictionless pulley to another body $\mathrm{B}$ also of mass $m$, sliding on a frictionless plane inclined at angle ${\theta }_2$ to the horizontal. Which of the following statements are true?

Two billiard balls$A$and $B$, each of mass $50\mathrm{g}$ and moving in opposite directions with speed of $5{\mathrm{ms}}^{-1}$ each, collide and rebound with the same speed. If the collision lasts for ${10}^{-3}s,$ which of the following statements are true?

 A body of mass $10 \mathrm{kg}$ is acted upon by two perpendicular forces, $6\mathrm{N}$ and $8\text{N.}$The resultant acceleration of the body is