Question

body of mass 1.5 kg thrown vertically upwards .Initial velocity is 15 meter per second . Wht will be the potential energy at end of 2 sec?

Answer 1

Hey!

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v= 15 m/s
m = 1.5 kg
t= 2s
g= 9.8 m/s^2

Distance after 2 s = 2×15 = 30
Potential energy = mgh
P.E = 1.5×9.8× 30
P.E = 441 J


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Hope it helps...!!!

Answer 2

Heya!

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A body of mass 1.5 kg thrown vertically upwards ;

u (initial velocity) = 15 m/s
g (acceleration due to gravity) = 10 m/s^2 (approx)

The velocity of ball after 2 seconds,

v = u + gt

=) v = 15 + (- 10*2)

Note : g is negative in case of upward motion.

=) v = 15 - 20

=) v = - 5 m/s

Hence final velocity of a ball is - 5 m/s.

Since v^2 = u^2 + 2gh

=) (-5)^2 = (15)^2 + 2(-10)(h)

=) 25 = 225 - 20h

=) 20h = 225 - 25

=) 20h = 200

=) h = 200m / 20

=) h = 10m.

Since Potential energy = m*g*h

=) Potential energy = 1.5 * 10 * 10 J

= 150 J

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Hope it's helpful to u.