Force

IMPORTANT

Force: Overview

This topic covers concepts such as Force, Properties of Force, Units of Force, Mass, Units of Mass, Aristotle Fallacy, Classification of Forces, Fundamental Forces, Field Forces, Contact Forces, Normal Reaction Force, Tangential Reaction Force, etc.

Important Questions on Force

EASY
IMPORTANT

The mass of a lift is 2000 kg. When the tension in the supporting cable is 28000 N, then its acceleration is :

MEDIUM
IMPORTANT

A block of mass m is placed on a smooth wedge of inclination   θ.  The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block (g is acceleration due to gravity) will be

MEDIUM
IMPORTANT

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

MEDIUM
IMPORTANT

A man weighing 80 kg, stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of   5m s 2 .  What would be the reading on the scale?   g=10m s 2  

EASY
IMPORTANT

If a cricketer catches a ball of mass 150 g moving with a velocity of 20 m s1, then he experiences a force of (Time taken to complete the catch is 0.1 s)

MEDIUM
IMPORTANT

A monkey is descending from the branch of a tree with constant acceleration. If the breaking strength is 75% of the weight of the monkey, the minimum acceleration with which monkey can slide down without breaking the branch is

MEDIUM
IMPORTANT

Block A of mass m and block B of mass 2m are placed on a fixed triangular wedge by means of a massless inextensible string and a frictionless pulley as shown in figure. The wedge is inclined at 45° to the horizontal on both sides. The coefficient of friction between block A and the wedge is 23 and that between block B and the wedge is 13. If the system of A and B is released from rest, find the magnitude and direction of the force of friction acting on A.

Question Image

MEDIUM
IMPORTANT

Two blocks of mass 2.9 kg and 1.9 kg are suspended from a rigid support S by two inextensible wires each of length 1 m see figure. The upper wire has negligible mass and the lower wire has a uniform mass of 0.2 kgm1 . The whole system of blocks, wires and support has an upward acceleration of 0.2 ms2 . Acceleration due to gravity is 9.8 ms2 .

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

(ii) Find the tension  T'  at the mid-point of the upper wire.


Question Image

EASY
IMPORTANT

A spring balance is attached to the ceiling of a lift. A man hangs his bag on the spring and the spring reads 49 N when the lift is stationary. If the lift moves downward with an acceleration of 5 m s2, the reading of the spring balance will be,

MEDIUM
IMPORTANT

Three forces acting on a body are shown in the figure. To have a resultant force only along the Y-axis, the magnitude of the minimum additional force needed is:

Question Image

EASY
IMPORTANT

The rough surface of a horizontal table offers a definite maximum opposing force to initiate the motion of a block along the table, which is proportional to the resultant normal force given by the table. Forces F1 and F2 act at the same angle θ with the horizontal and both are just initiating the sliding motion of the block along the table. Force F1 is a pulling force while the force F2 is a pushing force. F2 > F 1 , because

EASY
IMPORTANT

Consider following forces: (w) Force due to tension along a string, (x) Normal force given by a surface, (y) Force due to air resistance and (z) Buoyant force or upthrust given by a fluid. Which of these are electromagnetic forces?

MEDIUM
IMPORTANT

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

MEDIUM
IMPORTANT

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

MEDIUM
IMPORTANT

Block A of weight 100 N rests on a frictionless inclined plane of slope angle 30° as shown in the figure. A flexible cord attached to A passes over a frictionless pulley and is connected to block B of weight W. Find the weight W for which the system is in equilibrium.
Question Image

EASY
IMPORTANT

The force, that is not displacement dependent is:

EASY
IMPORTANT

What is the field force example?

MEDIUM
IMPORTANT

Explain weight and how it is different from mass?

 

 

 

MEDIUM
IMPORTANT

What is the concept of mass? What is difference between inertial and gravitational mass ?

EASY
IMPORTANT

Unification of weak and electromagnetic interactions was done by ____________