Answer:
1. G.P.E = 24 J
2. center of mass
Explanation:
Given the following data;
Mass = 2kg
Height, h = 1.2m
Acceleration due to gravity = 9.8 N/kg or m/s².
To find the gravitational potential energy;
Gravitational potential energy (GPE) is an energy possessed by an object or body due to its position above the earth.
Mathematically, gravitational potential energy is given by the formula;

Where;
- G.P.E represents potential energy measured in Joules.
- m represents the mass of an object.
- g represents acceleration due to gravity measured in meters per seconds square.
- h represents the height measured in meters.
Substituting into the formula, we have;

G.P.E = 23.52 to 2 S.F = 24 Joules.
Translation kinetic energy is defined as the energy of a system due to the motion of the system’s center of mass. The center of mass is typically where the mass of the object or particle is concentrated.
Answer:
200 C
Explanation:
Let C1 and C2 be their charges. According to Coulomb's law

where k =
is the constant, R = 0.4m is the distance between them, F = 120 N is their resulting charge force


Since their total charge is 200C:
or 
We can substitute the above equation


or
So the larger charge is C = 200 C
Answer:
Explanation:
We shall apply concept of impulse
Impulse = Force x time
= Force x 2 x 10⁻³ N.s
impulse = change in momentum
change in momentum
= .4 x 4 - ( - .4 x 2 )
= 2.4
Force x 2 x 10⁻³ = 2.4
Force = 2.4 / 2 x 10⁻³
= 1.2 x 10³ N .
average magnitude of the force exerted by floor = 1.2 x 10³ N
If R be reaction force by earth
R - mg = 1.2 x 10³
R = 1.2 x 10³ + mg
= 1200 + .4 x 9.8
= 1200 +3.92
= 1203 .92 N .
Explanation:
Given that,
Charge acting on the object, 
Force acting on the object,
(in downward direction)
(a) The electric force acting in the electric field is given by :

E is the electric field


E = 4.75 N/C
The direction of electric field is as same as electric force. But it is negative charge. So, the direction of electric field is in upward direction.
(b) The charge on the proton is, 
The force acting on the proton is :



If the charge on the proton is positive, the force on the proton is in upward direction.
Hence, this is the required solution.
Answer: I think the answer C
Explanation: