Common Forces in Mechanics

A monkey of mass $20 \mathrm{kg}$ is holding a vertical rope. The rope will not break when a mass of $25 \mathrm{kg}$ is suspended from it but will break if the mass exceeds $25 \mathrm{kg}$. What is the maximum acceleration with which the monkey can climb up along the rope? $\left(g=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$

Two blocks of mass $2.9 \mathrm{kg}$ and $1.9 \mathrm{kg}$ are suspended from a rigid support $S$ by two inextensible wires each of length $1 \mathrm{m}$ see figure. The upper wire has negligible mass and the lower wire has a uniform mass of $0.2 \mathrm{kg}{\mathrm{m}}^{-1}$ . The whole system of blocks, wires and support has an upward acceleration of $0.2 \mathrm{m}{\mathrm{s}}^{-2}$ . Acceleration due to gravity is $9.8 \mathrm{m}{\mathrm{s}}^{-2}$ .

(i) Find the tension $T$ at the mid-point of the lower wire.

(ii) Find the tension  $T^{\text{'}}$  at the mid-point of the upper wire.

A man weighing $60 \mathrm{kg}$ is in a lift moving down with an acceleration of $1.8 \mathrm{m} {\mathrm{s}}^{-2}$. The force exerted by the floor on him is

The viscous force the relative motion between the adjacent layers of a fluid in motion. Which one of the flowing fits best in the sentence

What are field forces explain?

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

Viscous forces are not present in

A man weighing $60 \mathrm{kg}$ is in a lift moving down with an acceleration of $1.8 \mathrm{m} {\mathrm{s}}^{-2}$. The force exerted by the floor on him is

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

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?

A $14 \mathrm{kg}$ block is hanged using a system of pulleys as shown in figure. Tension in string connecting celling and topmost pulley is :-

A block of mass $m$ is suspended by a light thread from an elevator. The elevator is accelerating upward with uniform acceleration $a$. The work done by tension on the block during $t$ seconds is $(u=0):$

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?