Answer:
160N
Explanation: When 80kg mass is one group . It's reaction force acting on a ground.
Weight of the object = 80*10
= 800 N
Here we are given cofficient of static friction its 0.2. It should be smaller than 1
Friction force = Reaction * Friction Cofficient
Reaction = 800N ( Considering Vertical Equilibrium )
F = 800* 0.2
F = 160N
Energy stored in a capacitor is Electric Potential Energy. Capacitor is device used for storing energy. The work done to charge is a capacitor is stored in it in the form of Electrical potential energy. Electrical potential energy is defined as capacity to do work due to the position change. For example, we know fans have capacitor installed in it. When we turn off the fan, it continue moving using the electrical energy stored in the capacitor.
<span>One result of a chemical change is letter B: A
new material is formed. Let us take for example on the paper being burned to
ashes. There is a clear use of heat or thermal energy as heat is transferred
from the medium to the paper, however, no energy is created, it only
transformed to other energy. Materials may change but it could also happen to
physical change like ice (which was in solid phase) turning or evaporating to
water (liquid phase).</span>
The answer 1 is
The best-known use of radio waves is for communication; television, cellphones and radios all receive radio waves and convert them to mechanical vibrations in the speaker to create sound waves that can be heard.Electromagnetic radiation is transmitted inwaves or particles at different wavelengths and frequencies.
the answer 2 is
Radio Waves: Instant Communication
Microwaves: Data and Heat
i think the answer number 3 is
It is all about wavelength versus tunnel diameter. The wavelength of GPS is about 20cm it would happily propagate in any normal tunnel if it could get in but the earth and other structures absorb it. AM radio (600kHz - 1500kHz) cannot propagate in any normal tunnel because the wavelength is too long (500m-200m) relative to the diameter, and thus gets reflected at the entrance. FM (100MHz ~ 3m) would propagate and it does for a while but then it suffers reflections
