Answer:
The speed of the rock when it is at height h/4 is 
.
Explanation:
At maximum height the final velocity of the rock is equal to 0. Let u is the initial velocity of the rock. Using the conservation of energy to find it as :
.......(1)
We need to find the speed of the rock when it is at height h/4. Let v' is the speed. Using 3rd equation of motion as :
here a = -g and s = h/4
Using equation (1) :
So, the speed of the rock when it is at height h/4 is . Hence, this is the required solution.
Answer:
options A and C
Explanation:
Since, the spheres are of same size and rotational speed of the sphere are not dependent on their masses. So, both the sphere will reach the bottom of the at the same time with the same speed. But their kinetic energies are different.
So, options A and C are correct.
Yes! with out the sun plants and animals wouldnt live right? therefore they get energey wich is passed on by food
Answer:
The correct question is:
"Find the energy each gains"
The energy gained by a charged particle accelerated through a potential difference is given by
where
q is the charge of the particle
is the potential difference
For a proton,
And since 
The energy gained by the proton is
For an alpha particle,
Therefore, the energy gained is
Finally, for a singly ionized helium nucleus (a helium nucleus that has lost one electron)
So the energy gained is the same as the proton:
Answer:
-17.5 nC
Explanation:
charge A = -30 nC
charge B = -5 nC
After adding them it would be the average of the two charges because of the getting same voltage difference. so
c = (-30+(-5)) / 2 nC
c= -17.5 nC
answer is -17.5 nC
