It is true that only half of the moon is always illuminated
by the sun. The reason why the moon
changes it phases is because Moon orbits around the Earth, and due to this some
areas of the half of the moon will not be lit by the sun.
Answer:
Some work input is lost to friction
Explanation:
The efficiency of a machine is defined as:
(1)
where
is the work output
is the work input
Due to the law of conservation of energy, the work output can never be larger than the work input (because energy cannot be created). Moreover, in real machines part of the work input is lost due to the presence of frictions: as a result, part of the energy in input is converted into thermal energy or other forms of energy, and so the work output is smaller than the work input, and so the ratio (1) becomes less than 1, and so the efficiency is less than 100%.
Answer:
At 11 AM, the train is a constant speed of 110 km/h. when the truck is 160 ahead. When they meet, it will be 2 PM
Explanation:
At the train's first hour he moved to 110 km. The truck is at 160 km. The second hour includes train at 220 km, with truck at 240. At 2 PM, they are at the same place.
Answer:
-78.4 cm
Explanation:
We can solve the problem by using the lens equation:
where
p is the distance of the object from the lens
q is the distance of the image from the lens
f is the focal length
Here we have
p = 80.0 cm
q = -39.6 cm (negative, because the image is on the same side as the object , so it is a virtual image)
Substituting, we find f:
Answer:
d. 332 V
Explanation:
Given;
number of turns in the wire, N = 40 turns
area of the coil, A = 0.06 m²
magnitude of the magnetic field, B = 0.4 T
frequency of the wave, f = 55 Hz
The maximum emf induced in the coil is given by;
E = NBAω
Where;
ω is angular velocity = 2πf
E = NBA(2πf)
E = 40 x 0.4 x 0.06 x (2 x π x 55)
E = 332 V
Therefore, the maximum induced emf in the coil is 332 V.
The correct option is "D"
d. 332 V