The main reason as to why those telescopes that are located above the Earth's atmosphere is because the atmosphere absorbs infrared light which comes from the sun and this affects the viewing done by the astronomers. That is why, this is considered as a great disadvantage for those ground-based telescopes. The answer would be the last option.
Answer: 0.00068 N
Explanation: Universal gravitational constant=6.674 *10^(-11)
Force=Gm1m2/(r^2)
Force= 6.67*25000*40000*10^(-11)/(10^2)
Force=0.00068 N
Answer:
Explanation:
STEP 1
<u>Given</u>
Radius of cylinder = r = 25cm, 2.5m
mass = 27kg
cylinder is mounted so as to rotate freely about a horizontal axis that is parallel to and 60cm to the central logitudinal axis of the cylinder
height = 0.6m
<u>part 1</u>
The cylinder is mounted so as to rotate freely about a horizontal axis tha is paralle to 60cm from the central longitudinal axis of then cylinder. The rotational inertia of the cylinder about the axis of rotation is given by
<em>I = Icm + mh²</em>
<em>∴ I = 1/2mr² + mh² = 1/2x27x (0.5)² + 20 x (0.6)²</em>
<em>I=13.09kg.m²</em>
where
<em>I</em>cm is the rotational inertia of the cylinder about its central axis
m is the mass of the cylinder
h is the distance between the axis of the rotation and the central axis of the cylinder
r is the radius of the cylinder
<em> </em><em> I=13.09kg.m²</em>
<em>part2</em>
<em>from the conservation of the total mechanical energy of the meter stick, the change in gravitational potential energyof the meter stick plus the change in kinetic energy must be zero</em>
<em>Δk + Δu = 0</em>
<em>1/2 </em>I(w²-w²) = Ui-Uf
1/2 x 13.09w² = mgh
∴w=√20 x 9.8 x 0.6/(1/2 x 13.09) =117.6/6.5
w=18.09rad/s
We Know, W = F * s
here, F = 25 N
s = 3 m
Substitute it into the expression,
W = 25 * 3
W = 75 Joule
So, your final answer is 75 J
Hope this helps!
Answer:
The correct answer is from Tech B.
Explanation:
The relay is an electromagnetic device, which is stimulated by a very weak electrical current to open or close a circuit. It functions as a switch controlled by an electrical circuit in which, by means of a coil and an electromagnet, a sequence of one or several contactors is activated that allow to open or close other electrical circuits independent of the one that controls it.
Have a nice day!
