Question 1 :
Two objects of masses $ m_1$ and $m_2$ having the same size are dropped simultaneously from heights $ h_1$ and $h_2$ respectively. What will the ratio of time they would take in reaching the ground be if both of them are hollow, size remaining the same in each case?
Question 3 :
Amit buys few grams of gold at the poles as per the instruction of one of his friends. He hands over the same when he meets him at the equator. Will the friend agree with the weight of gold bought?
Question 4 :
A ball is thrown vertically upwards with a velocity of 49 m/s.What is the total time it takes to return to the surface of the earth?
Question 5 :
What is the source of centripetal force that a planet requires to revolve around the Sun?
Question 6 :
A stone is thrown vertically upward with an initial velocity of 40 m/s. Taking g = 10 $m/s^2$,What is the net displacement and the total distance covered by the stone?
Question 7 :
Why does a block of plastic released under water come up to the surface of water?
Question 8 :
Why is the weight of an object on the moon$\frac{1}{6}th$ its weight on the earth?
Question 9 :
The volume of 50 g of a substance is 20 $cm^3$. If the density of water is 1 $g cm^{–3}$, will the substance float or sink?
Question 10 :
The universal law of gravitation explained several phenomena,which of these is not one of them ?
Question 11 :
The weight of any person on the moon is about $\frac{1}{6}$ times that on the earth. He can lift a mass of 15 kg on the earth. What will be the maximum mass, which can be lifted by the same force applied by the person on the moon?
Question 12 :
The earth and the moon are attracted to each other by gravitational force. Does the earth attract the moon with force that is greater or smaller or the same as the force with which the moon attracts the earth?
Question 13 :
What happens to the force between two objects, if the distance between the objects is tripled?
Question 14 :
A girl stands on a box having 60 cm length, 40 cm breadth and 20 cm width in three ways. In which of the following cases, pressure exerted by the brick will be:
Question 18 :
An object is thrown vertically upwards and rises to a height of 10 m.What is the velocity with which the object was thrown upwards?
Question 19 :
The value of acceleration due to gravity of the earth is-
Question 20 :
A ball thrown up vertically returns to the thrower after 6 s.What is its position after 4 s?