Answer:
when the direction of the Current changes.
Explanation:
Electromagnet refers to an iron ore wrapped around with a coil of wire, in presence of electric current. As it acts like a magnet, when current is passed through it.
The north & south poles of magnetic fields produced by such magnet, change with direction of current passed through it.
Answer:
Explanation:
height of pole = 15 ft
height of man = 6 ft
Let the length of shadow is y .
According to the diagram
Let at any time the distance of man is x.
The two triangles are similar
15 y - 15 x = 6 y
9 y = 15 x
Differentiate with respect to time.
As given, dx/dt = 4 ft/s
ft/s
Answer:
h = 4271.43 m
Explanation:
given,
Volume of the water = 1 m³
temperature decrease by = 10°C
heat removed from water
Q = m c ΔT
Q = ρ V c ΔT
= 1000 × 1 × 4186 × 10
= 4.186 × 10⁷ J
energy is used to do work to move the water against its weight
Q = force × displacement
4.186 × 10⁷ J = m g × h
4.186 × 10⁷ J = 1000 × 1 × 9.8 × h
h = 4271.43 m
hence, the change in height of is equal to h = 4271.43 m
A). No. A mirror doesn't separate light into its different wavelengths.
B). No. Light doesn't separate into its different wavelengths when it
goes, say, from glass into water.
C). No. When light goes through your glasses, it doesn't separate
into its different wavelengths.
D). Yes ! When sunlight shines into droplets of water in the atmosphere,
it comes out separated into its different wavelengths. When we see that
happening in the air in front of us, we call it a "rainbow".
Answer:
A heavy ball of demolition machine is storing energy when it is held at an elevated position .
