U=0
<span>t=10 </span>
<span>a=9.8m/s/s </span>
<span>v is velocity (the tower must be very high to be able to fall for 10 seconds!!!) </span>
<span>you work out the result now</span>
<span>Friction
can help us play tennis, knock down bowling pins, and cook dinner.</span>
We have the equation of motion 
, where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.
Here s = 300 m, u = 0 m/s, a = 9.81 
Substituting
Now we have v = u+at, where v is the final velocity
Here u = 0 m/s, a= 9.81 and t = 7.82 seconds
Substituting
v = 0+9.8*7.82 = 76.68 m/s
The speed with which the penny strikes the ground = 76.68 m/s.
Answer:
Why sex cells only need half the number of chromosomes compared to other cells in the body? As gametes are produced, the number of chromosomes must be reduced by half. Why? The zygote must contain genetic information from the mother and from the father, so the gametes must contain half of the chromosomes found in normal body cells.
Explanation:
Brainliest Plzz
