Advertisements
Advertisements
प्रश्न
What do you understand by the term energy? Is energy a scalar or vector? How is the energy possessed by a body measured?
Advertisements
उत्तर
Energy is defined as the capacity of a body to do work. Energy is a scalar quantity. The energy possessed by a body is measured by the amount of work done by a body while changing its state of rest or state of motion.
APPEARS IN
संबंधित प्रश्न
Name a common device where a gear train is used
When does a force perform work?
.A man raises a box of mass 50kg to a height of 2m in 20s, while another man raises the same box to the same height in 50s. Compare:
(i) the work done, and
(ii) the power developed by them.
A body of mass 5 kg falls from a height of 10 m to 4 m. Calculate:
The loss in potential energy of the body,
What is the work done against gravity when a body is moved horizontally along a frictionless surface?
If an electric bulb of 100 watt is lighted for 2 hours, how much electric energy would be consumed?
(i) A 200g ball is thrown vertically upward with an initial velocity of 30 ms-1. Draw a velocity-time graph for the motion of ball.
(ii) How long will the ball take to reach the highest point?
(iii) What will be the kinetic energy of ball, when it returns to the starting point, neglecting the air resistance?
(iv) What will be the potential energy of ball at highest point?
The work done by the heart is 1 Joule per beat. Calculate the power of the heart if it beats 72 times in one
