A reference point is a point in geometry or general which is used to determine or refer to another point. In reference to this point, measurements can be done. Like, a reference point in space is used to measure distance or displacement to another point. A reference point in time is used to measure the time interval of an event. A reference in space-time can be used to measure the speed or detect object's motion. Hence, the following points apply:
→A position from which to measure future distance
→a set of standard units for measuring displacement
→a method for determining the speed of an object
→a way to detect an object’s motion
A reference point provides a way/method to infer information about the object.
Answer:
16.2 days
Explanation:
Find the number of halflives:
1/2 * 1/2 = 1/4 so <u>two</u> halflives have passed
2 * 8.1 days = 16.2 days
Explanation:
F=15000/0.02
=300N
total area contact of the shoes and floor when stood in one foot=0.02m^2/2=0.01m^2
P=F/A
=300/0.01
=30 000Pa/30 000Nm^-2
in another way=15000×2
=30000N/m^2
If the elevator's speed is constant (in ANY direction) and you can't see out of it, then there's NO measurement you can make inside that will tell you that it's moving. Any weight you measure is normal.
Answer:
62.5 %
Explanation:
Let the initial intensity of unpolarized light is Io.
After first polariser the intensity of light becomes I'.
So, 
Now it passes through another polariser. The angle between the first polariser and the second polariser is given by Ф. The intensity is I''.
According to the law of Malus
Here, Ф = 30 degree
The percentage change in the intensity is given by
= 62.5 %
