Solve the following and express each answer in scientific notation and to the correct number of significant figures. a). (5.3 x 10^4) + (1.3 x 10^4) b). (7.2 x 10^-4) /(1.8 x 10^3 c). 10^4 x 10^-3 x 10^6 d). (9.12 x 10^-1) - (4.7 x10^-2 e). (5.4 x 10^4) x (3.5 x 10^9)

Scientific notation always have a decimal part multiplied by 10 raised to the exponent of a positive or negative integer.

a)

b)

c)

d)

e)

When working on multiplication and division of numbers in scientific notation, the laws of indices are applied as shown in the results above.

For addition and subtraction, the both numbers in scientific notation must be made to have a common exponent before the operation can be carried out successfully.

Also note that the correct number of significant figure must be maintained in the results obtained from each operation.

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a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

1. they vary with a higher number because boiling is way hotter than melting