Advertisements
Advertisements
प्रश्न
List all the forces acting on (a) the pulley A, (b) the boy and (c) the block C in figure.

Advertisements
उत्तर
Forces acting on the pulley A :
- A tension exerts electromagnetic force between the string and pulley A.
- A pair of gravitational force between the Earth and pulley.
Forces acting on the boy :
- A tension exerts electromagnetic force between the string and the boy.
- A pair of gravitational force between the Earth and the boy.
Forces acting on the block C :
- A tension exerts electromagnetic force between the string and block C.
- A pair gravitational force between block C and the Earth.
APPEARS IN
संबंधित प्रश्न
State if the following statement is true or false. Give a reason for your answer.
Work done in the motion of a body over a closed loop is zero for every force in nature.
A boy is sitting on a chair placed on the floor of a room. Write as many action-reaction pairs of forces as you can.
Is it true that the reaction of a gravitational force is always gravitational, of an electromagnetic force is always electromagnetic and so on?
Figure shows a cart. Complete the table shown below.

| Force on | Force by | Nature of the Force | Direction |
| Cart |
1 |
||
| Horse |
1 |
||
| Driver |
1 |
When Neils Bohr shook hand with Werner Heisenberg, what kind of force they exerted ?
The sum of all electromagnetic forces between different particles of a system of charged particles is zero
Two spherical bodies, each of mass 50 kg, are placed at a separation of 20 cm. Equal charges are placed on the bodies and it is found that the force of Coulomb repulsion equals the gravitational attraction in magnitude. Find the magnitude of the charge placed on either body.
The average separation between the proton and the electron in a hydrogen atom in ground state is 5.3 × 10−11 m. (a) Calculate the Coulomb force between them at this separation. (b) When the atom goes into its first excited state the average separation between the proton and the electron increases to four times its value in the ground state. What is the Coulomb force in this state?
The work done by all the forces (external and internal) on a system equals the change in ______.
A block of mass m slides down a smooth vertical circular track. During the motion, the block is in
A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the plane. The motion of the particle takes place in a plane. It follows that
(a) its velocity is constant
(b) its acceleration is constant
(c) its kinetic energy is constant
(d) it moves in a circular path.
A particle moves from a point \[\overrightarrow{r}_1 = \left( 2 m \right) \overrightarrow{ i } + \left( 3 m \right) \overrightarrow{ j } \] to another point
\[\overrightarrow{r}_2 = \left( 3 m \right) \overrightarrow{ i } + \left( 2 m \right) \overrightarrow{ j } \] acts on it. Find the work done by the force on the particle during the displacement.
A block of mass 250 g slides down an incline of inclination 37° with uniform speed. Find the work done against friction as the block slides through 1m.
A block of mass m is kept over another block of mass M and the system rests on a horizontal surface (In the following figure). A constant horizontal force F acting on the lower block produces an acceleration \[\frac{F}{2 \left( m + M \right)}\] in the system, and the two blocks always move together. (a) Find the coefficient of kinetic friction between the bigger block and the horizontal surface. (b) Find the frictional force acting on the smaller block. (c) Find the work done by the force of friction on the smaller block by the bigger block during a displacement d of the system.

Find the average frictional force needed to stop a car weighing 500 kg at a distance of 25 m if the initial speed is 72 km/h.
A block of mass 2 kg kept at rest on an inclined plane of inclination 37° is pulled up the plane by applying a constant force of 20 N parallel to the incline. The force acts for one second. Find the work done by the force of gravity in that one second if the work done by the applied force is 40 J.
A block of mass 2.0 kg is pushed down an inclined plane of inclination 37° with a force of 20 N acting parallel to the incline. It is found that the block moves on the incline with an acceleration of 10 m/s2. If the block started from rest, find the work done (a) by the applied force in the first second, (b) by the weight of the block in the first second and (c) by the frictional force acting on the block in the first second. Take g = 10 m/s2.
A block of mass 1 kg is placed at point A of a rough track shown in figure following. If slightly pushed towards right, it stops at point B of the track. Calculate the work done by the frictional force on the block during its transit from A to B.

The work done by a variable force is calculated using the formula:
When force varies non-linearly with displacement, what method must be used to find work?
