Answer:

Explanation:
From the question we are told that
Nucleus diameter 
a 12C nucleus
Required kinetic energy 
Generally initial speed of proton must be determined,applying the law of conservation of energy we have

where
=initial kinetic energy
=final kinetic energy
=initial electric potential
=final electric potential
mathematically

where
=distance b/w charges
=nucleus charge 
=constant
=proton charge
Generally kinetic energy is know as

Therefore
Generally equation for radius is 
Mathematically solving for radius of nucleus


Generally we can easily solving mathematically substitute into v_1









Therefore the proton must be fired out with a speed of 
Answer:

Explanation:
A charge located at a point will experience a zero electrostatic force if the resultant electric field on it due to any other charge(s) is zero.
is located at the origin. The net force on it will only be zero if the resultant electric field intensity due to
and
at the origin is equal to zero. Therefore we can perform this solution without necessarily needing the value of
.
Let the electric field intensity due to
be +
and that due to
be -
since the charge is negative. Hence at the origin;

From equation (1) above, we obtain the following;

From Coulomb's law the following relationship holds;

where
is the distance of
from the origin,
is the distance of
from the origin and k is the electrostatic constant.
It therefore means that from equation (2) we can write the following;

k can cancel out from both side of equation (3), so that we finally obtain the following;

Given;

Substituting these values into equation (4); we obtain the following;


Answer:
Heat energy required (Q) = 3,000 J
Explanation:
Find:
Mass of water (M) = 200 g
Change in temperature (ΔT) = 15°C
Specific heat of water (C) = 1 cal/g°C
Find:
Heat energy required (Q) = ?
Computation:
Q = M × ΔT × C
Heat energy required (Q) = Mass of water (M) × Change in temperature (ΔT) × Specific heat of water (C)
Heat energy required (Q) = 200 g × 15°C × 1 cal/g°C
Heat energy required (Q) = 3,000 J
Answer: Final speed
Explaination: because its final.