Hi!
The energy of the block is 4 m/s
To calculate this, you need to use the equation for
kinetic energy. The block is sliding (i.e. it's moving). If the object is sliding across a level surface, the only energy it has is kinetic energy, because
there is no change in potential energy (which changes with height). So, the mechanical energy will be pure kinetic energy. The equation is the following, derived from the expression for kinetic energy:

Have a nice day!
Answer:
The two poles of the bar magnet change positions. The compass needle spins a half circle.
Explanation:
The thin atmosphere of Mars is thought to be due to the planet's lack of a magnetic field, which has allowed the Solar wind to blow away much of the gas the planet once had. Venus, despite still having a thick atmosphere of CO2, surprisingly has a similar problem
You have to figure it out
I think the correct answer is C