The Forces Physics - The Forces

Is it true that the reaction of a gravitational force is always gravitational, of an electromagnetic force is always electromagnetic and so on?

List all the forces acting on:

1. The pulley A.
2. The boy and.
3. The block C in figure.

A body builder exerts a force of 150N against a bullworker and compresses it by 20cm. Calculate the spring constant of the spring in the bullworker.

A monkey is sitting on a tree limb. The limb exerts a normal force of 48N and a frictional force of 20N. Find the magnitude of the total force exerted by the limb on the monkey.

The force with which the earth attracts an object is called the weight of the object. Calculate the weight of the moon from the following data: The universal constant of gravitation G = 6.67 × 10^-11N-m²/kg², mass of the moon = 7.36 × 10²²kg, mass of the earth = 6 × 10²⁴kg and the distance between the earth and the moon = 3.8 × 10⁵km.

A lawyer alleges in court that the police has forced his client to issue a statement of confession. What kind of force is this?

Figure shows a cart. Complete the table shown.

At what distance should two charges, each equal to 1C, be placed so that the force between them equals your weight?

The average separation between the proton and the electron in a hydrogen atom in ground state is 5.3 × 10^-11 m.

1. Calculate the Coulomb force between them at this separation.
2. 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 geostationary orbit of the earth is at a distance of about 36000km from the earth's surface. Find the weight of a 120kg equipment placed in a geostationary satellite. The radius of the earth is 6400km.

Suppose the magnitude of Nuclear force between two protons varies with the distance between them as shown in figure. Estimate the ratio "Nuclear force/Coulomb force" for:

1. x = 8fm
2. x = 4fm
3. x = 2fm
4. x = 1fm (1fm = 10^-15m).

Calculate the force with which you attract the earth.

When Neils Bohr shook hand with Werner Heisenberg, what kind of force they exerted?

1. Gravitational.
2. Electromagnetic.
3. Nuclear.
4. Weak.

The two ends of a spring are displaced along the length of the spring. All displacement have equal magnitudes. In which case or cases the tension or compression in the spring will have a maximum magnitude?

1. The right end is displaced towards right and the left end towards left.
2. Both ends are displaced towards right.
3. Both ends are displaced towards left.
4. The right end is displaced towards left and the left end towards right.

The sum of all electromagnetic forces between different particles of a system of charged particles is zero:

1. Only if all the particles are positively charged.
2. Only if all the particles are negatively charged.
3. Only if half the particles are positively charged and half are negatively charged.
4. Irrespective of the signs of the charges.

A proton exerts a force on a proton which is:

1. Gravitational.
2. Electromagnetic.
3. Nuclear.
4. Weak.

Which of the following systems may be adequately described by classical physics?

1. Motion of a cricket ball.
2. Motion of a dust particle.
3. A hydrogen atom.
4. A neutron changing to a proton.

Two spherical bodies, each of mass 50kg, are placed at a separation of 20cm. 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.

A satellite is projected vertically upwards from an earth station. At what height above the earth's surface will the force on the satellite due to the earth be reduced to half its value at the earth station? (Radius of the earth is 6400km.)

Two charged particles placed at a separation of 20cm exert 20N of Coulomb force on each other. What will be the force if the separation is increased to 25cm?