Explain main type of force with suitable example.
Force is required to bring to body at rest, to motion or to stop moving body. It is not always necessary to be in contact of the body. Hence, there are mainly two type of force.
$(i)$ Contact Force :
In contact force there is physical interaction between objects. Due to contact with other body state of motion or rest of an object can be changed.
Contact force act on both object in contact.
Contact force can be push or pull.
Block lying on table can be given push or it can be pulled.
- Here contact force act on both object.
$(ii)$ Field Force :
When an object is in gravitational field, magnetic field or electric field it experience force due to field.
In field force there is no physical interaction between object.
Magnetic force, electric force or gravitational force are example of field force.
An object falling freely from top of a building has accelerated motion due to gravitational field of the earth.
Here, there is no physical contact between the earth and object in motion still it has accelerated motion.
When nail is placed near bar magnet, it is attracted due to magnetic field of bar magnet.
A rope of length $10\, m$ and linear density $0.5\, kg/m$ is lying lengthwise on a smooth horizontal floor. It is pulled by a force of $25\, N$. The tension in the rope at a point $8\, m$ away from the point of application is ....... $N$
In the figure shown, $A$ & $B$ are free to move. All the surfaces are smooth. then $(0 < \theta < 90^o)$
If net force on a system is zero then
Three blocks $A$, $B$ and $C$ are pulled on a horizontal smooth surface by a force of $80 \mathrm{~N}$ as shown in figure
The tensions $T_1$ and $T_2$ in the string are respectively
Two masses $m$ and $M$ are attached to the strings as shown in the figure. If the system is in equilibrium, then