Answer:
Visible Light and Radio waves
Explanation:
The earth's atmosphere is transparent to a few windows in the electromagnetic spectrum. it is completely transparent to allow observation from the ground in visible light rang 380 to 740 nano meters. Also in the range of radio wave as communication are done from space to ground in the form of radio waves.
it is Partially transparent to Microwave and infrared range.
If it produces 20J of light energy in a second, then that 20J is the 10% of the supply that becomes useful output.
20 J/s = 10% of Supply
20 J/s = (0.1) x (Supply)
Divide each side by 0.1:
Supply = (20 J/s) / (0.1)
<em>Supply = 200 J/s </em>(200 watts)
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Here's something to think about: What could you do to make the lamp more efficient ? Answer: Use it for a heater !
If you use it for a heater, then the HEAT is the 'useful' part, and the light is the part that you really don't care about. Suddenly ... bada-boom ... the lamp is 90% efficient !
Work = (force) x (distance)
1,008 J = (force) x (28 m)
Divide each side by 28m : (1,008 kg-m²/sec²) / (28 m) = force
Force = 36 kg-m/s² = 36 Newtons .
(about 8.1 pounds)
It doesn't matter what that force accomplishes.
It could be moving a brick, lifting a fish, or pushing a little red wagon.
In order to do 1,008 joules of work in 28 meters, it takes 36 N of force,
in the direction of the 28 meters.
Answer:
(a) I=0.01 kg.m²
(b) I=0.03 kg.m²
Explanation:
Given data
Mass of disk M=2.0 kg
Diameter of disk d=20 cm=0.20 m
To Find
(a) Moment of inertia through the center of disk
(b) Moment of inertia through the edge of disk
Solution
For (a) Moment of inertia through the center of disk
Using the equation of moment of Inertia
For (b) Moment of inertia through the edge of disk
We can apply parallel axis theorem for calculating moment of inertia
Answer:
The circular loop experiences a constant force which is always directed towards the center of the loop and tends to compress it.
Explanation:
Since the magnetic field, B points in my direction and the current, I is moving in a clockwise direction, the current is always perpendicular to the magnetic field and will thus experience a constant force, F = BILsinФ where Ф is the angle between B and L.
Since the magnetic field is in my direction, it is perpendicular to the plane of the circular loop and thus perpendicular to L where L = length of circular loop. Thus Ф = 90° and F = BILsin90° = BIL
According to Fleming's left-hand rule, the fore finger representing the magnetic field, the middle finger represent in the current and the thumb representing the direction of force on the circular loop.
At each point on the circular loop, the force is always directed towards the center of the loop and thus tends to compress it.
<u>So, the circular loop experiences a constant force which is always directed towards the center of the loop and tends to compress it.</u>
