Common Forces In Mechanics - Practice Questions & MCQ

An object resting on a table, is shown in the figure below. The mass of the object is 1 kg. Acceleration due to gravity is $9.8 \frac{\mathrm{~m}}{s^2}$. Determine the normal force (in N ) exerted on the object by the table.

Two objects resting on a table. Mass of object 1 (m₁) = 1 kg, mass of object 2 (m₂) = 2 kg, Acceleration due to gravity (g) =9.8 m/s². Determine the magnitude and direction of the normal force (R₁) exerted by m₂ on the m₁ and the normal force (R₂) exerted by the table on the m₂.

An Atwood machine has masses 5Kg and 15 Kg as shown. What is the acceleration (in m/s²) at 15 Kg  mass when the system is released from rest 

A body of mass 1 kg lies on a smooth inclined plane. A force F=10m is applied horizontally on the block as shown. The magnitude of normal reaction by the inclined plane on the block is

A massless rope is fixed at one end as shown in Fig. Two boys of masses 40 kg and 60 kg are moving along the rope. The former climbs up with an acceleration of $2 \mathrm{~m} / \mathrm{s}^2$ while later coming down with a constant velocity of $5 \mathrm{~m} / \mathrm{s}$. The tension (in N ) at fixed support will be ( $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2$ )

A spring whose unstretched length is I has a force constant k. The spring is cut into two pieces of unstretched lengths $l_1$ and $l_2$ where $l_1=n l_2$ and n is an integer. The ratio $k_1 / k_2$ of the corresponding force constants, $k_1$ and $k_2$ will be:

A $\sqrt{34} \mathrm{~m}$ long ladder weighing 10 kg leans on a frictionless wall. Its feet rest on the floor 3 m away from the wall as shown in the figure. If $\mathrm{F}_{\mathrm{f}}$ and $\mathrm{F}_{\mathrm{w}}$ are the reaction forces of the floor and the wall, then ratio of $\mathrm{F}_{\mathrm{w}} / \mathrm{F}_{\mathrm{f}}$ will be:

$
\left(\text { Use } g=10 \mathrm{~m} / \mathrm{s}^2 .\right)
$
 

A monkey of mass 50 kg climbs on a rope which can withstand the tension $(\mathrm{T})$ of 350 N . If monkey initially climbs down with an acceleration of $4 \mathrm{~m} / \mathrm{s}^2$ and then climbs up with an acceleration of $5 \mathrm{~m} / \mathrm{s}^2$. Choose the correct option $\left(\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2\right)$.

A steel block of 10 kg rests on a horizontal floor as shown. When three iron cylinders are placed on it as shown, the block and cylinders go down with an acceleration $0.2 \mathrm{~m} / \mathrm{s}^2$. The normal reaction $\mathrm{R}^{\prime}$ by the floor if the mass of the iron cylinders is equal and of 20 kg each, is $\qquad$ N. [Take $g=10 \mathrm{~m} / \mathrm{s}^2$ and $\mu_s=0.2$ ]

A block of mass M lies on smooth inclined plane. A force of 15 N is applied horizontally on the block as shown. The magnitude of normal by inclined plane on the block is  , if the block is in equilibrium condition