Answer:
The potential energy (P.E) at the top is 392 J
The kinetic energy (K.E) at the top is 0 J
The potential energy (P.E) at the halfway point is 196 J.
The kinetic energy (K.E) at the halfway point is 196 J.
Explanation:
Given;
mass of the rock, m = 2 kg
height of the cliff, h = 20 m
speed of the rock at the halfway point, v = 14 m/s
The potential energy (P.E) and kinetic energy (K.E) when its at the top;
P.E = mgh
P.E = (2)(9.8)(20)
P.E= 392 J
K.E = ¹/₂mv²
where;
v is velocity of the rock at the top of the cliff = 0
K.E = ¹/₂(2)(0)²
K.E = 0
The potential energy (P.E) and kinetic energy (K.E) at the halfway point;
P.E = mg(¹/₂h)
P.E = (2)(9.8)(¹/₂ x 20)
P.E = 196 J
K.E = ¹/₂mv²
where;
v is velocity of the rock at the halfway point = 14 m/s
K.E = ¹/₂(2)(14)²
K.E = 196 J.
<h3><u>Answer</u>;</h3>
C. An object can have acceleration with negative velocity.
<h3><u>Explanation</u>;</h3>
- Acceleration is a measure of the change in velocity over time. The change in velocity is measured in meter per second (m/s), and time interval is measured in second (s).
- Therefore, acceleration measures the change in meters per second every second [(m/s)/s], namely meters per second per second or meters per second squared (m/s2).
- If an object has zero acceleration, its velocity doesn’t have to be zero. Acceleration is a measure of the change in velocity over time. Zero acceleration means there is no change in velocity over time, namely constant velocity.
Answer: The ball would exert and equal force on the astronaut in the opposite direction. Both would move away from each other in a straight path. Hope this helps!
Answer:
Explanation:
Given:
mass of lead chunk, 
height of the fall, 
- Assuming the collision to be perfectly inelastic the whole kinetic energy of the chunk is lost after the collision.
- Here when the chunk is at the given height it has a potential energy which on falling transforms into kinetic energy of the chunk.
So, increase in the internal energy of the system after the collision is :
