11. A seesaw sits in static equilibrium. A child with a mass of 30 kg sits 1 m away from a pivot point. Another child sits 0.75
m away from the pivot point on the opposite side. The second child's mass is _____ kg.
1 answer:
Answer:
<h2>40 kg</h2>Explanation:
Find the diagram relating to the question for proper explanation of the question below.
Using the principle of moment
Sum of clockwise moments = Sum of anticlockwise moments
Moment = Force * perpendicular distance
For anti-clockwise moment:
Since the 30 kg moves in the anticlockwise direction according to the diagram
ACW moment = 30 * 1 = 30 kgm
For clockwise moment
If another child sits 0.75 m away from the pivot point on the opposite side, moment of the child in clockwise direction = M * 0.75 = 0.75M (M is the mass of the unknown child).
Equating both moments we have;
0.75M = 30
M = 30/0.75
M = 40 kg
The second child's mass is 40 kg
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Answer:
Large binocular telescope, Keck 1 telescope, Hobby-Ebberly telescope, Subaru telescope, Gemini North telescope, Magellan 2 telescope
Explanation:
How much light a telescope can collect depends on its diameter, since in a bigger area more photons will be collected.
Remember that in a circle the area is defined as:
(1)
Where A is the area and r is its radius.
However, the radius can be determined by means of its diameter.
(1)
Where d is its diameter.
An example of this is when a person is collecting raindrops with a bucket and with a cup. Since the bucket has a bigger area than the cup, it will collect more raindrops by unit of time. In this scenario the raindrops represent the photons.
To determine the light collecting area of each telescope, equation 2 will be replaced in equation 1.
(3)
Case for Large binocular telescope:
For the second mirror will be the same value
Case for Keck 1 telescope:
Case for Hobby-Ebberly telescope:
Case for Subaru telescope:
Case for Gemini North telescope:
Case for Magellan 2 telescope:
Hence, they may be rank in the following way:
Large binocular telescope, Keck 1 telescope, Hobby-Ebberly telescope, Subaru telescope, Gemini North telescope, Magellan 2 telescope.
<em>Key term:</em>
<em>Photons: particles that constitute light. </em>