Answer:
A
Explanation:
Given that a stone dropped from the top of a 80m high building strikes the ground at 40 m/s after falling for 4 seconds. The stone's potential energy with respect to the ground is equal to its kinetic energy. (use 9 - 10 m/s)
O at the moment of impact
2 seconds after the stone is released after the stone has fallen 40 m
when the stone is moving at 20 m/s
At the top of the hill, the P.E = mgh
P.E = 10 × 80 × m
P.E = 800m
At the moment of impact, K.E = 1/2mv^2
K.E = 1/2 × 40^2 × m
K.E = 1/2 × 1600 × m
K.E = 800m
Since both P.E and K.E are the same, we can therefore conclude that the stone's potential energy with respect to the ground is equal to its kinetic energy at the moment of impact.
The correct answer is option A.
The loudness would increase
Answer: YES
Explanation:
If Tia Ana exposes her eyes to light ray in which it frequency is higher than ultraviolet ray, it may result to a gradual eyes issue such as cataracts as the radiation damages the cornea and the lens in front of the eyes.
Answer:
2000 times 5.
Explanation:
5 credits, and its 2000 for 1 credit. boom there you go an answer
