Answer:
ΔU = 2 mg h
Explanation:
In a spring mass system the potential energy is U = m g h
where h is measured from the equilibrium point of the spring
the potential energy at the highest point is
U₁ = m g h
the potential energy at the lowest point is
U₂ = m g (-h)
instead in this energy it is
ΔU = 2 mg h
In this two points the kinetic energy is zero, but there is elastic potential energy that has the same value in the two points, so its change is zero
Answer:
a.18.5 m/s
b.1.98 s
Explanation:
We are given that

a.Let
be the initial velocity of the ball.
Distance,x=30 m
Height,h=1.8 m





Substitute the values





Initial velocity of the ball=18.5 m/s
b.Substitute the value then we get

t=1.98 s
Hence, the time for the ball to reach the target=1.98 s
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