Answer:
4 times greater
Explanation:
<u>Step 1:</u> Calculate light-collecting area of a 20-meter telescope (A₁) by using area of a circle.
Area of circle = π*r² =
Where d is the diameter of the circle = 20-m


A₁ = 314.2 m²
<u>Step 2:</u> Calculate light-collecting area of a 10-meter Keck telescope (A₂)

Where d is the diameter of the circle = 10-m

A₂ = 78.55 m²
<u>Step 3</u>: divide A₁ by A₂

= 4
Therefor, the 20-meter telescope light-collecting area would be 4 times greater than that of the 10-meter Keck telescope.
The positive plate is made of lead grid with a lead oxide paste coating and the negative plate is porous lead. Dilute sulphuric acid is the electrolyte. The lead acid battery produced a direct current or DC during a chemical reaction that turns lead dioxide to lead sulphate and sulphuric acid to water.
Answer:
<em>b. The current in the loop always flows in a counterclockwise direction.</em>
<em></em>
Explanation:
When a magnet falls through a loop of wire, it induces an induced current on the loop of wire. This induced current is due to the motion of the magnet through the loop, which cause a change in the flux linkage of the magnet. According to Lenz law, the induced current acts in such a way as to repel the force or action that produces it. For this magnet, the only opposition possible is to stop its fall by inducing a like pole on the wire loop to repel its motion down. An induced current that flows counterclockwise in the wire loop has a polarity that is equivalent to a north pole on a magnet, and this will try to repel the motion of the magnet through the coil. Also, when the magnet goes pass the wire loop, this induced north pole will try to attract the south end of the magnet, all in a bid to stop its motion downwards.
The car’s momentum after 4.21s is 24617.4 kgm/s
<h3>
Newton's Second Law of Motion.</h3>
Newton's second law state that, the rate of change of momentum, is directly proportional to the applied force.
Given that a 1200 kg car passes traffic light at a velocity of 10.2 m/s to the north and accelerates at a rate of 2.45 m/s^2. To calculate the car’s momentum after 4.21 s, Let us first list all the parameters involved.
- Acceleration a = 2.45 m/s²
From Newton's second law,
F = (mv - mu) / t
ma = (mv - mu) / t
Substitute all the parameters into the formula above.
1200 × 2.45 = ( mv - 1200 × 10.2 ) / 4.21
2940 = ( mv - 12240 ) / 4.21
Cross multiply
12377.4 = mv - 12240
Make mv the subject of the formula
mv = 12377.4 + 12240
mv = 24617.4 kgm/s
Therefore, the car’s momentum after 4.21s is 24617.4 kgm/s
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Answer:
2917.4 m/s
Explanation:
From the question given above, the following data were:
Gravitational acceleration of the Moon (g) = 0.25 times the gravitational acceleration of the earth
Radius (r) of the Moon = 1737 Km
Escape velocity (v) =?
Next, we shall determine the gravitational acceleration of the Moon. This can be obtained as follow:
Gravitational acceleration of the earth = 9.8 m/s²
Gravitational acceleration of the Moon (g) = 0.25 times the gravitational acceleration of the earth
= 0.25 × 9.8 = 2.45 m/s²
Next, we shall convert 1737 Km to metres (m). This can be obtained as follow:
1 Km = 1000 m
Therefore,
1737 Km = 1737 Km × 1000 m / 1 Km
1737 Km = 1737000 m
Thus, 1737 Km is equivalent to 1737000 m
Finally, we shall determine the escape velocity of the rocket as shown below:
Gravitational acceleration of the Moon (g) = 2.45 m/s²
Radius (r) of the moon = 1737000 m
Escape velocity (v) =?
v = √2gr
v = √(2 × 2.45 × 1737000)
v = √8511300
v = 2917.4 m/s
Thus, the escape velocity is 2917.4 m/s