Advertisements
Advertisements
Question
Choose one or more correct alternatives.
Joule is the unit of ______.
- force
- work
- power
- energy
Solution
Joule is the unit of work and energy.
APPEARS IN
RELATED QUESTIONS
State two conditions when no work is done by a force.
Define the term energy.
What are the two kinds of mechanical energy?
A force of 30 N acts on a body and moves it through a distance of 5 m in the direction of force. Calculate the work done by the force.
A machine raises a load of 750 N through a height of 16 m in 5 s. calculate:
- energy spent by machine,
- power at which the machine works.
Find the kinetic energy of a body of mass 1 kg moving with a uniform velocity of 10 m s-1.
What are the quantities on which the amount of work done depends? How are they related to work?
Write the formula for work done on a body when the body moves at an angle to the direction of force. Give the meaning of each symbol used.
Give one example each in which a force does (a) positive work (b) negative work, and (c) zero work.
Determine the amount of work done when an object is displaced at an angle of 30° with respect to the direction of the applied force.
What is the work done when the object acted upon by a force remains at rest?
Name the physical quantity whose MKS units are kgm2s-3.
State the energy changes which take place when A piece of magnesium wire is burnt in a jar of oxygen.
State the energy changes which take place when A stone dropped from the top of a cliff reaches the ground after some time.
A coolie is pushing a box weighing 1500 N up an inclined plane 7.5 m long on to a platform, 2.5 m above the ground.
(i) Calculate the mechanical advantage of the inclined plane. (ii) Calculate the effort applied by the coolie.
(iii) In actual practice, the coolie needs to apply more effort than what is calculated. Give one reason why you think the coolie needs to apply more effort.
