Answer:

Explanation:
Using the conservation of energy we have:

Let's solve it for v:

So the speed at the lowest point is 
Now, using the conservation of momentum we have:

Therefore the speed of the block after the collision is 
I hope it helps you!
Flow of electrons through a copper wire
Answer:
I think like 2024 or 25
Explanation:
Elon musk will probably go
Answer:
This is because the force of gravity is much less on the moon than on the earth, therefore the person wont be pulled down much and will jump higher
Explanation:
A wavefront is the long edge that moves, for example, the crest or the trough. Each point on the wavefront emits a semicircular wave that moves at the propagation speed v. These are drawn at a time t later, so that they have moved a distance s = vt.