Answer:
Explanation:
Exact numbers are those numbers which are known with 100% certainty or accuracy . Numbers having decimal are generally not exact because they are a part of long drawn decimal number after rounding off to certain places after decimal.
On the basis of this definition we can say as follows
speed of light is 2.99792 ×108 . Here the number quoted is not an exact number because it is a rounded off figure of speed of light to five digits after decimal .
Similarly density of mercury too is rounded off to two digits after decimal
so it is also not a exact number.
There are 3600 s in 1 h . Here 3600 s is an exact number because one hour has been defined as 3600 s . It is not measured by any instrument.
In 2003, the United States had 50 states. Here 50 is an exact number .
Option (B) is correct.Energy contained in one gram of matter=9 x 10¹³ J
Explanation:
mass= 1 g= 0.001 kg
c= velocity of light= 3 x 10⁸ m/s
The mass energy equivalence equation is given by
E = m C²
E= (0.001)(3 x 10⁸)²
E=9 x 10¹³ J
Thus energy contained in one gram of matter=9 x 10¹³ J
Answer:
I would say a pond
Explanation:
A pond is more still than an ocean, therefore you could see your reflection better
I think its C not sure tho
When the magnet is placed on the glass, it is attracted to the iron filings. The pattern of the iron filings shows that the lines of force that make up the magnetic field of the magnet. Also, The lines of force of north and south poles attract each other whereas those of two north poles fend off each other.
