Question 11 :
Can any object have mechanical energy even if its momentum is zero?
Question 12 :
A mass of 10 kg is at a point A on a table. It is moved to a point B. If the line joining A and B is horizontal, what is the work done on the object by the gravitational force?
Question 13 :
The sum of the potential energy and kinetic energy of the object would be the same at all points. That is, potential energy + kinetic energy = constant.
Question 14 :
A light and a heavy object have the same momentum. Find out the ratio of their kinetic energies. Which one has a larger kinetic energy?
Question 15 :
Write an expression for the work done when a force is acting on an object in the direction of its displacement.
Question 16 :
A body is falling from a height h. After it has fallen a height $\frac{h}{2}$ , it will possess
Question 18 :
1 J is the amount of work done on an object when a force of 1 N displaces it by ____ along the line of action of the force.
Question 19 :
Soni says that the acceleration in an object could be zero even when several forces are acting on it. State true or false.
Question 20 :
Certain force acting on a 20 kg mass changes its velocity from 5 $\frac{m}{s}$to 2 $\frac{m}{s}$. Calculate the work done by the force.
Question 21 :
What precautions can you take in your school to reduce the incidence of infectious diseases?
Question 23 :
A baby is not able to tell her/his caretakers that she/he is sick. What would help us to find out what is the sickness?
Question 24 :
For water-borne microbes, we can prevent exposure by providing safe drinking water. TRUE or FALSE?
Question 25 :
One of the basic principle of prevention of infectious disease is the non-availability of proper and sufficient food for everyone. TRUE or FALSE?
Question 26 :
A baby is not able to tell her/his caretakers that she/he is sick. What would help us to find out that the baby is sick?
Question 28 :
What are the different means by which infectious diseases are spread?
Question 30 :
Under which of the following conditions are you most likely to fall sick?