Explanation:
a) The height of the ball h with respect to the reference line is

so its initial gravitational potential energy
is



b) To find the speed of the ball at the reference point, let's use the conservation law of energy:

We know that the initial kinetic energy
as well as its final gravitational potential energy
are zero so we can write the conservation law as

Note that the mass gets cancelled out and then we solve for the velocity v as



Answer:
The particle which completes the given equation is :
Explanation:
The given reaction is of a fission reaction:

Total mass on the reactant side is equal to the total mass on the product side:
239 + 1 = 100 +A+ 2
A = 138
Sum of atomic numbers on the reactant side is equal to the sum of atomic number on the product side:
94 + 1(0) = 40 + Z + 2(0)
Z = 54
So atomic number 54 id of Xenon.
The particle which completes the given equation is :

The speed of the runner is 300 m /38 seconds. You can simplify this answer to be about 7.9 m/s
Answer:
6.32m/s
Explanation:
note:Now these calculations are based in the fact that acc. due to gravity is 10m/s²
okay so I'm thinking you think the speed of a body depends on the mass of the body also,umh... well it doesn't at all!
when two bodies of different masses fall from the same height,they fall at the same time( this is just to say)
now enough of the talking let solve....
so the ball was dropped .ie from rest to the ground through a distance of 2m,
the formula for calculating the distance if a body moving in a straight line is given by:
S=ut + ½at² where u is initial velocity, a is acceleration ( of the body or due to gravity, but since its falling freely under the influence of gravity its " we use the acceleration due to gravity ,which is 10m/s²) and t is the time taken to cover the distance.
from our question the ball was dropped from rest thus its u is 0 therefore we use this equation to find the time it took to touch ground (S=½at²)
solving ....
we get t to be 0.632s
to find the speed we substitute t in the equation below:
V=u+at ,but since u=0
V=at =10•0.632=6.32m/s
therefore the speed the body uses to strike the ground is 6.32m/s