Answer:
A. Sound comes from the ball every time it bounces.
B. The ball is warmer after it stops bouncing than it was before it
started bouncing
Explanation:
It is evidently shown that the ball shown energy transformation because it produces sound at each bounce and also becomes warmer after the bounce.
The law of conservation of energy suggests that energy is neither created nor destroyed but transformed from one form to another.
- a bouncing ball produces sound energy at each bounce. This is conversion of potential energy initially of the ball into kinetic energy of sound.
- Also, the motion of the ball produces kinetic energy which causes the ball to warm up, this is thermal energy.
- We see that a ball originally with potential energy has yielded the kinetic forms of energy which are sound and thermal energy.
Answer:
1120 N
Explanation:
The velocity with which he hits the water can be found with kinematics:
v² = v₀² + 2aΔy
v² = (0 m/s)² + 2 (-9.8 m/s²) (-9.00 m)
v = -13.3 m/s
Or it can be found with conservation of energy.
PE = KE
mgh = ½ mv²
v = √(2gh)
v = √(2 × -9.8 m/s² × -9.00 m)
v = -13.3 m/s
Sum of forces on the diver after he hits the water:
∑F = ma
F − mg = m Δv/Δt
F − (74.0 kg) (9.8 m/s²) = (74.0 kg) (0 m/s − (-13.3 m/s)) / (2.50 s)
F = 1120 N
Answer:
A. Brahe and Kepler
Explanation:
The Copernican model was a heliocentric model of the universe. Copernicus thought that the Sun is stationary, and the Earth and the other planets are orbiting around it. He also noted that the stars are further away from the Sun compared to the distance between the Earth and the Sun. Three very important hings in his theory are that he thought that the Earth rotates around its own axis, revolves around the Sun, and has annual tilting of its axis. At some things, Copernicus was right with his theory, at some he wasn't, but anyway he made one giant step forward in the understanding of the universe. His theory was supported by many, though mostly after his death, with one of the most noticeable supporters of him being Ticho Brache and Kepler who made model of his theory, as well as improving it.
Before going to answer this question first we have to know the fundamental principle of magnetism.
A magnet have two poles .The important characteristic of a magnet is that like poles will repel each other while unlike poles will attract each other.
Through this concept the question can be answered as explained below-
A-As per first option the side of magnet A is repelled by the south pole of magnet B. Hence the pole of a must be south .It can't be north as it will lead to attraction.
B-The side of magnet A is repelled by the north pole of magnet B. Hence the side of A must be north pole.It can't be a south pole.
C-The side of magnet A is attracted by the south pole of magnet B .Hence the side of magnet A must be north.Hence this is right
D-The side of magnet A is attracted by the north pole of magnet B. Hence the side of A must south.It can't be north as it will lead to repulsion.
Hence the option C is right.
An inclined plane has less of a mechanical advantage because it has to have more work to take so,etching up than down. I hope this makes sense.
