Answer:
Since it is falling freely, the only force on it is its weight, w.
w = m × g = 250 kg × 9.8 m/s^2 = 2450 Newton/N
Answer:

Work done to bring three electrons from a great distance apart to 3.0×10−10 m from one another (at the corners of an equilateral triangle) is 
Explanation:
The potential energy is given by:
U=Q*V
where:
Q is the charge
V is the potential difference
Potential Difference=V=
So,

Where:
k is Coulomb Constant=
q is the charge on electron=
r is the distance=
For 3 Electrons Potential Energy or work Done is:


Work done to bring three electrons from a great distance apart to 3.0×10−10 m from one another (at the corners of an equilateral triangle) is 
Answer:
Light shone on metal expulses electrons from its surface. This phenomenon is the photoelectric effect, and the electrons are called photoelectrons. Experiments indicate that by increasing light frequency, the kinetic energy of the photoelectrons increases, and by intensifying the light, the current increases
Answer:
Area = 20 m²
Explanation:
Given the following data;
Force = 2500 N
Pressure = 125 Pa
To find the area on which it rest;
Mathematically, pressure is given by the formula;

Making area the subject of formula, we have;

Substituting into the formula, we have;

Area = 20 m²
A heat pump is a device that is capable of transferring heat energy from a source of heat to what is known as the heat sink. It also moves thermal energy in the opposite direction of a spontaneous heat transfer through heat absorption from a cold space and releasing it to a warmer space.
When a heat pump is being utilized for heating, it employs the same principle with that of the refrigeration cycle used by an air conditioner or a refrigerator, but in the opposite direction since it releases heat into a conditioned space rather than the surrounding environment. Moreover, heat pump resembles much as refrigeration since it has the same components with the latter except for the presence of a reverse valve.