Answer: 4m
Explanation:
Since the angle of incidence of a plane mirror can be anything from 0 to 90°
Assuming that the place is a perfectly square 4×4m room
The incident ray would be 45° for the choir(object) at a 4m distance, this is still within the range of values.
We do not forget also, that the focal length of a plane mirror is infinity, the organist would in fact see farther than 4m if need be. And wider
Answer:
D) negative, due to extra electrons.
Explanation:
The charge that would be gained will be negative charges due to extra electrons.
Electrons are usually lost or gained by bodies that comes in contact with one another.
They occupy the orbital space in an atom and are not strongly held by forces within the atom.
Protons cannot be lost in such manner. They occupy the nucleus and are bounded by strong chemical forces within it.
The polythene and rods are both made up of chemical substances whose units called atoms are made up of subatomic particles of protons, neutrons and electrons. As with all kinds of matter, there would be pool of free electrons round them that can easily be rubbed off due to the weak attractive forces binding them in the atomic sphere.
When the polythene and rods are rubbed, there would be a loss of electrons and the gaining body, polythene becomes negatively charged.
Answer:
The wavelength of light is 68 nm
Explanation:
<span>On the scale the only external forces are the man's weight acting downwards and the normal force which the scale exerts back to support his weight.
So F = Ma = mg + Fs
The normal force Fs (which is actually the reading on the scale) = Ma + Mg
But a = 0
So Fs = Mg which is just his weight.
Fs = 75 * 9.8 = 735N</span>
