I agree with you the answer is A
Answer:
1.53m
Explanation:
Given parameters:
Mass of box = 3kg
Gravitational potential energy = 45J
Unknown
Height of the box = ?
Solution:
To solve this problem;
Gravitational potential energy = mgh
m is the mass
g is the acceleration due to gravity
h is the height
45 = 3 x 9.8 x h
h = 1.53m
Answer:
94.13 ft/s
Explanation:
<u>Given:</u>
= time interval in which the rock hits the opponent = 10 s - 5 s = 5 s
= distance to be moved by the rock long the horizontal = 98 yards
= displacement to be moved by the rock during the time of flight along the vertical = 0 yard
<u>Assume:</u>
= magnitude of initial velocity of the rock
= angle of the initial velocity with the horizontal.
For the motion of the rock along the vertical during the time of flight, the rock has a constant acceleration in the vertically downward direction.

Now the rock has zero acceleration along the horizontal. This means it has a constant velocity along the horizontal during the time of flight.

On dividing equation (1) by (2), we have

Now, putting this value in equation (2), we have

Hence, the initial velocity of the rock must a magnitude of 94.13 ft/s to hit the opponent exactly at 98 yards.
Color property of light would provide evidence for the idea that light is a wave
<h3><u>
Explanation:</u></h3>
The reality is that light manifests practices that are representative of both waves and particles. Young proposed that light of varying colors was formed of waves possessing various lengths, a basic theory that is popularly believed today. In contradiction, the particle theory advocates envisioned that several colors were obtained from particles holding either various masses or moving at various speeds.
All waves are perceived to experience refraction when they transpire from one means to another means. Light, similar to any wave, is apprehended to refract as it transfers from one medium into another medium.