Question

A body of mass 10 kg projected vertically upward from the ground has
potential energy 580 joules and kinetic energy of 1380 joules at a certain point
in its path. The velocity of projection of the body must be:
a) 15.5 m/s b) 18.7m/s c) 14m/s d) 10.7 m/s REF​

Answer 1

K.E at point of launch = total M.E. (since these as no P.E at launch)

=580+1380 (since there is no non-conservation force, so ME is conserved)

⇒

2

1

mv

2

=1960

⇒v

2

=

5

1960

⇒v=19.8 m/s

Answer 2

Answer:

K.E at point of launch = total M.E. (since these as no P.E at launch)

=580+1380 (since there is no non-conservation force, so ME is conserved)

1/2 mv² = 1960

v²=1960/5 = 19.8m/s

Explanation:

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