Common Forces in Mechanics

What are field forces explain?

The locus of the reaction of a two hinged semi-circular arch is

A force is said to be variable if its magnitude or direction changes with position or time.

A box of mass $25 \mathrm{kg}$ starts from rest and slides down an inclined plane $8$ metre long and $5$ metre high. It is found to move at the bottom at $7 \mathrm{m}/\sec .$ What is the force of friction? $\left(\mathrm{g}=9.8 \mathrm{m}/{\mathrm{s}}^2\right)$

When a person walks on a surface, the frictional force exerted by the surface on the person is opposite to the direction of motion. True or false?

When walking on ice one should take short steps. Why?

There is a limit beyond which the polishing of a surface increases frictional resistance rather than decreasing it why?

When, two ends of an ideal spring are pulled apart increasing its length it produces force equal to $kx$ at its ends. At a point $\frac{1}{4}$ of its length from one end, the force is

The system shown in the figure is released from rest. Pulley and spring are massless and friction is absent everywhere. The speed of $5 \mathrm{kg}$ block when $2 \mathrm{kg}$ block leaves the contact with ground is $\left(K=40 \mathrm{N} {\mathrm{m}}^{-1} \& \mathrm{g}=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$

Tangential reaction force is a type of contact force.

Identify the tangential reaction force from the following.

What is tangential reaction force? Explain with an example.

Four identical uniform rods of mass m = 6 kg each are welded  their ends to form a square and then welded to a uniform ring having mass m = 4 kg and radius R = 1m. The system is allowed to roll down he incline of inclination $\text{θ}=30^{\circ }$

The force of friction between the system and the plane is

Four identical uniform rods of mass m = 6 kg each are welded  their ends to form a square and then welded to a uniform ring having mass m = 4 kg and radius R = 1m. The system is allowed to roll down he incline of inclination $\text{θ}=30^{\circ }$

The acceleration of centre of mass of system is

Which of the following are contact force/forces?

In the given picture, which is the correct force/forces that come into play?

Suraj’s dad wants to take his car to a garage. But the car is unable to move. So, he calls a rescue van to pull the car to the garage. Which of the following forms of force will help in this case?

Non-stick frying pans are coated with a material called Teflon which does not allows the food to stick to the pan. Which of the following forces is low on a Teflon surface?

In cold countries the car tyres have chains tied to them so that driving on snow becomes easier. The chain increases the force of friction between the surface and the tyre. Do you think this is a correct explanation?

In an elevator, a system is arranged as shown in the figure. Initially, the elevator is at rest and the system is in equilibrium with the middle spring unstretched. When the elevator accelerates upwards, it was found that for the new equilibrium position (with respect to the lift), the further extension in the top spring is $1.5$ times that of the further compression in the bottom spring irrespective of the value of acceleration.

If $k_1=k_2=k_3=500 \mathrm{N} {\mathrm{m}}^{-1}$ and $m_1=2 \mathrm{kg}$ and the acceleration of the elevator is $2.5 \mathrm{m} {\mathrm{s}}^{-2}$, find the tension in the middle spring in final equilibrium with respect to the lift.