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uranmaximum [27]
3 years ago
7

A rock is thrown straight upward with an initial velocity of 20 m/s where the downward acceleration due to gravity is -10 m/s^2.

How long is the ball in the air before it returns to the thrower's hand?
Physics
1 answer:
Afina-wow [57]3 years ago
7 0

Answer:

4 seconds

Explanation:

Given:

Δy = 0 m

v₀ = 20 m/s

a = -10 m/s²

Find: t

Δy = v₀ t + ½ at²

0 m = (20 m/s) t + ½ (-10 m/s²) t²

0 = 20t − 5t²

0 = 5t (4 − t)

t = 4

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Answer:

\boxed{\sf Tension \ in \ the \ string \ (T) = 3 \ kN}

Given:

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\therefore

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3 years ago
A 3 kg rock sits on a 0.8 meter ledge. If it is pushed off, how fast will it be going at the bottom?
andrey2020 [161]

As long as it sits on the shelf, its potential energy
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