Answer:
The correct option is (b).
Explanation:
Given that,
At the top of the hill, the kinetic energy is E and the gravitational potential energy is 3E.
We need to find the kinetic energy of the car on the ground.
We know that,
Mechanical energy = kinetic energy + potential energy
According to the law of conservation of energy, the total mechanical energy is conserved.
It means, when it coasts down to ground level, the kinetic energy is same as that on the top of the hill. Hence, the required kinetic energy on the ground is equal to 3E.
A 40-gallon gas water heater can recover in about an hour. But a Recovery for a 40-gallon electric water heater takes about two hours.But I'm not so sure about a water tank
Just use the formula
speed=Frequency X Wavelength
where speed of electromagnetic waves in vacuum is always 3X10^8
Answer:
160m/s
Explanation:
The speed of a wave is related to its frequency and wavelength, according to this equation:
v=f ×λ
