Heat energy and thermal energy are the same because heat energy is thermal energy. Also thermal energy and temperature are the same because temperature is measuring heat in degrees Celsius or degrees Fahrenheit. Hope this helps!
You could answer this right away IF you knew the length of each wave, right ?
Well, Wavelength = (speed) / (frequency).
Speed = 3 x 10⁸ m/s (the speed of light)
and
Frequency = 90.9 x 10⁶ Hertz.
So the length of each wave is 3 x 10⁸ / 90.9 x 10⁶ meters.
To answer the question, see how many pieces you have to cut
that 1.5 km into, in order for each piece to be 1 wavelength.
It'll be
(1,500 meters) divided by (3 x 10⁸ meters/sec) / (90.9 x 10⁶ Hz)
To divide by a fraction, flip the fraction and then multiply:
(1500 meters) times (90.9 x 10⁶ Hz)/(3 x 10⁸ meters/sec)
= 454.5
Explanation:
a) Balloon is being thrown down and is speeding up;
mg > 
b) Balloon is in the air on its way down and moving with constant speed.
=mg
c) The Balloon is on the ground and rest instantaneously
mg = Normal
d) Balloon is moving slowly downward;
e) Because, at the peak of trajectory drag force is 0.
Drag force = 0
