Answer:
• 36.4 kg of coal.
• 80 pounds of coal.
Explanation:
Using proportionality constant,
Mass of coal = 1,000,000/27,500,000 btus/metric ton
= 0.0364 metric tons of coal
Mass of coal = 1,000,000/25,000,000 btus/ton
= 0.04 tons of coal.
Converting metric tons to kilogram,
1 metric ton = 1000kg,
0.0364 metric ton;
= 36.4 kg of coal.
Converting tons to pounds,
1 ton = 2000 pounds,
0.04 metric ton;
= 80 pounds of coal.
A scientific law is the simple mathematical expression of the relationship involved. A principle is the same relationship expressed in words. A theory is the explanation of the facts that make up the relationship.
The source of the earth's magnetic field is found in the ;LIQUID MAGNETIZED IRON IN THE CORE OF THE EARTH. The earth's magnetic field is believed to be generated very deep down in the earth's core as a result of molten iron which it contains.
60 RPM equals one hertz (i.e., one revolution per second, or a period of one second). The SI unit for period is the second.
Answer:
a)
b)
c)
d)
e)
Explanation:
Given that:
- initial speed of turntable,
- full speed of rotation,
- time taken to reach full speed from rest,
- final speed after the change,
- no. of revolutions made to reach the new final speed,
(a)
∵ 1 rev = 2π radians
∴ angular speed ω:
where N = angular speed in rpm.
putting the respective values from case 1 we've
(c)
using the equation of motion:
here α is the angular acceleration
(b)
using the equation of motion:
(d)
using equation of motion:
(e)
using the equation of motion:
