The expression for kinetic energy of a body of mass m and velocity. Class 9
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The expression for kinetic energy of a body of mass m and velocity. Class 9
Question 1.
Fill in the blanks.
(i) Work done = _____ × _______ (in the direction of force).
Answer:
Work done = Force x Displacement (in the direction of force). W = F × s.
(ii) 1 joule of work is done when a force of ______ newton displaces an object by 1 metre in the direction of the force.
Answer:
1 (one). 1 J = 1 N × 1 m.
(iii) The expression for kinetic energy of a body of mass m and velocity v is _________.
Answer:
K = 1/2 mv².
(iv) The potential energy of an object of mass m at a small height h from the Earth’s surface is
Answer:
U = mgh (where g = 10 m s-2 near Earth's surface).
(v) Power is defined as the ______ at which work is done.
Answer:
Rate. Power is the rate at which work is done: P = W/t.