Weightlessness

A block weighing $30 \mathrm{N}$ is on a smooth horizontal surface and it is accelerated in the horizontal direction at the rate of $4 \mathrm{m} {\mathrm{s}}^{-2}$ by a force. The net force acting on the block is
$\left(g=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$

Weight of a body of mass $m$ in its free fall above the surface of the earth is

Weightlessness of an astronaut moving in a satellite is a situation of -

How much faster than its present speed should the earth rotate so that bodies lying on the equator may fly off into

Choose the INCORRECT option.

Weightlessness in satellite is due to

Write a short note on two stage rocket.

What is the function of first stage of the two stage rockect?

The radius of earth is about $6400 \mathrm{km}$ and that of mars is $3200 \mathrm{km}.$ And mass of the earth is about $10$ times mass of mars. An object weighs $200 \mathrm{N}$ on the surface of earth. Then its weight on the surface of mars will be

Astronauts feel weightless, because gravity is zero in the satellite.

In an artificial satellite, the object used is :

Describe how an artificial satellite using two-stage rockets is launched in an orbit around the earth.

Explain why an astronaut in an orbiting satellite has a feeling of weightlessness.

Explain why is it necessary to use a minimum two stage rocket to launch a satellite into a circular orbit around the earth.

What is the gravitational force exerted on a mass called?

What is the mass of a Person the surface of Jupiter if the gravitational pull of Jupiter is $20 N/Kg$ and he weighs $1,600$ N?

Ten coins are placed on top of each other on a horizontal table. If the mass of each coin is $10 \mathrm{g}$ and acceleration due to gravity is 10 $\mathrm{m} {\mathrm{s}}^{-2}$ , what is the magnitude and direction of the force on the $7^{\mathrm{t}\mathrm{h}}$ coin (counting from the bottom) due to all the coins above it?

A body weights 200 N at the surface of earth. If it be placed in an artificial satellite revolving at height where acceleration due to gravity is half of that at earth's surface. It will weigh

Assertion: In a free fall, weight of a body becomes effectively zero.

Reason: Acceleration due to gravity acting on a body having free fall is zero.

Assertion: A body falling freely under gravity becomes weightless.

Reason: $R=m (g - a)=m (g - g)$= zero.