Kinetic energy = (1/2) (mass) (speed)²
Before slowing down, the car's speed is 25 m/s,
and its kinetic energy is ...
(1/2) (1,500 kg) (25 m/s)²
= (1/2) (1,500 kg) (625 m²/s²)
= 468,750 joules .
After slowing down, the car's speed is 15 m/s,
and its kinetic energy is ...
(1/2) (1,500 kg) (15 m/s)²
= (1/2) (1,500 kg) (225 m²/s²)
= 168,750 joules.
The car lost (468,750 - 168,750) = 300,000 joules of K.E.
The law of Conservation of Energy says:
That 300,000 joules had to go somewhere.
If it's a standard, gas-powered car, then the kinetic energy got
put into the brakes. The energy turned into heat, and the heat
was carried off in the air.
If it's a more modern electric or hybrid car, then the kinetic energy
spun the wheel motors, turning them temporarily into electrical
generators. The generators converted the kinetic energy into
electrical energy, which got put back into the car's batteries, and
could be used again. That's why electric cars use less gas.
Answer:
false. the medium never moves
Explanation:
Answer:
F = 268 Hz
Explanation:
The beat frequency is given as:
|
So, for the first flute and tuning fork:
where,
F = Frequency of tuning fork
F = 248 Hz ± 20 Hz
F = 268 Hz (OR) 228 Hz
Now, for the second flute and tuning fork:
where,
F = Frequency of tuning fork
F = 288 Hz ± 20 Hz
F = 268 Hz (OR) 308 Hz
Since, 268 Hz is common from both calculations. Therefore, it will be the frequency of the tuning fork.
<u>F = 268 Hz</u>
Answer:
the Corona is about 10 million times less dense than sun's surface.this low density makesuch less bright than surface of the sun
