Answer:
Check the attached image
Explanation:
To solve the problem for time you will have to use the formula for time, t = d/s which means time equals distance divided by speed.
Kindly check the attached image below for the step by step explanation to the question.
V = f * wavelength
as we know electromagnetic wave has speed equal to light, so
3 * 10^8 = f * 1.3
f = 2.3 * 10^8 hertz
f = 230 mega hertz
Answer:
a)

b)

Explanation:
a)
= mass of the asteroid = 43000 kg
= initial speed of asteroid = 7600 m/s
= final speed of asteroid = 5000 m/s
= Work done by the force on asteroid
Using work-change in kinetic energy theorem

b)
= magnitude of force on asteroid
= distance traveled by asteroid while it slows down = 1.4 x 10⁶ m
Work done by the force on the asteroid to slow it down is given as

Answer: DC Current
Explanation:
Battery is a source of constant potential difference and it will create a constant voltage across any conductor
due to this constant voltage difference the current in this conductor will remain constant
So here since the voltage across the conductor is constant so we can say that current in the conductor will remain constant and hence this is known as DC current.
While for variable current in direction and magnitude is to be obtained only when the conductor is connected with AC voltage source as we know that AC voltage is variable with magnitude and direction both
A battery is the power source for DC type of current. A battery is a source of constant potential difference that produces a constant current unlike in AC source where the voltage and hence the current changes its polarity continuously.Hence, the current produced by battery is direct current and not Alternating current.
Hope this helps........ Stay safe and have a Merry Christmas!!!!!! :D