Embibe Experts Solutions for Chapter: Laws of Motion, Exercise 10: Exercise (Assertion & Reason)

The same spring is attached with $2 \mathrm{kg}$, $3 \mathrm{kg}$ and $1 \mathrm{kg}$ blocks in three different cases as shown in the figure. If $x_1$, $x_2$ and $x_3$ be the respective extensions in the spring in these three cases, then:-

Two forces ${\overrightarrow{F}}_1=\left(3 \mathrm{N}\right)\hat{\mathrm{i}}-\left(4 \mathrm{N}\right)\hat{\mathrm{j}}$ and ${\overrightarrow{F}}_2=-\left(1 \mathrm{N}\right)\hat{\mathrm{i}}-\left(2 \mathrm{N}\right)\hat{\mathrm{j}}$ act on a point object. In the given figure which of the eight vectors represents ${\overrightarrow{F}}_1$ and ${\overrightarrow{F}}_2$? What is the magnitude of the net forces?

Two weights w₁ and w₂ are connected by a light thread which passes over a light smooth pulley. If the pulley is raised upwards with an acceleration equal to g, then the tension in the thread will be :-

Three blocks of masses $m$, $3m$ and $5m$ are connected by massless strings and pulled by a force $F$ on a frictionless surface as shown in the figure below. The tension $P$ in the first string is $16 \mathrm{N}$.

If the point of application of $F$ is changed as given below, the values of $V$ and $Q^{\text{'}}$ shall be:-

In the figure given, the system is in equilibrium. What is the maximum value $W$ can have if the friction force on the $40 \mathrm{N}$ block cannot exceed $12.0 \mathrm{N}$?

Three blocks, of masses m₁= 2.0, m₂ = 4.0 and m₃ = 6.0 kg are connected by strings on a frictionless inclined plane of 60°, as shown in the figure. A force F = 120 N is applied upwards along the incline to the uppermost block, causing an upward movement of the blocks. The connecting cords are light. The values of tensions T₁ and T₂ in the cords are :

Assertion: In the inertial frame centrifugal force can’t appear.

Reason: In the uniform, circular motion centripetal force will counterbalance the centrifugal force.

Assertion: A quick collision between two bodies is more violent than a slow collision, even when the initial and the final velocities are identical.

Reason: Because the rate of change of momentum which determines the force is greater in the first case.