Answer:
Zero
Explanation:
Acceleration is rate of change of velocity..
Answer: A force must cause a displacement in order for work to be done. A book falls off a table and free falls to the ground. Yes. This is an example of work.
Explanation:
You should back-up your computer every few weeks (or as often as needed).
As soon as you suspect that your computer (or any other backup-able device) is too slow or "glitch-y" you should back-up your device before you lose any important files or data.
PREVENTING MALFUNCTION:
→ Always set your computer on a hard & flat surface.
→ Avoid downloading programs from unknown or non-trusted sources.
→ Avoid using your computer in a hot area.
→ Consider installing a virus/malware protection software on your computer.
B. There Is 4 Valence Electrons!
We use the equation of motion,
Here, S is the height, u is initial velocity and a is acceleration.
Given, 
As acorn falls from tree, therefore we take the value of 
and initial velocity 
.
Substituting these values in equation of motion,
Thus, the time taken by the acorn to fall 20 feet ( 6.096 m ) is 1.12 s.
