Answer:
6.21 m/s
Explanation:
Using work energy equation then

where d is displacement from initial to final position, v is velocity and subscripts a and b are position A and B respectively, m is mass of collar, g is acceleration due to gravity
Substituting 1 Kg for m, 0.4m for h,
as 0, 9.81 for g then

Answer:
<em>Total momentum is conserved</em>
Explanation:
<u>Conservation of Momentum
</u>
The momentum is a physical magnitude that measures the product of the object's velocity by its mass. The total momentum of a system is the sum of all its components' individual momentums. The two-bear system starts with a total moment of

When both bears stick together, the total mass is 20 kg, and the new momentum is

We have assumed both bears move to the right after the collision. In this situation, the total momentum is conserved
<span>C is the correct answer. Electron microscopes require a vacuum to work, so living cells cannot be seen because they cannot respire. Light microscopes use a ray of visible light instead of a beam of electrons to magnify something so it can be seen by the naked eye. There are two different types of electron microscope: transmission (TEM) and scanning (SEM).</span>