When you heat a certain substance with a difference of temperature

the heat (energy) you must give to it is

where

is the specific heat of that substance (given in J/(g*Celsius))
In this case

Observation: the specific heat of a substance is given in J/(g*Celsius) or J/(g*Kelvin) because on the temperature scale a
difference of 1 degree Celsius = 1 degree Kelvin
Explanation:
speed of wave
v = wavelength x frequency
since frequency is f = 1/Period then
v = wavelength : Period
v = 10 cm/ 0.2 s = 50 cm/s
v = 0.5 m/s
The problem states that the distance travelled (d) is
directly proportional to the square of time (t^2), therefore we can write this in
the form of:
d = k t^2
where k is the constant of proportionality in furlongs /
s^2
<span>Using the 1st condition where d = 2 furlongs, t
= 2 s, we calculate for the value of k:</span>
2 = k (2)^2
k = 2 / 4
k = 0.5 furlongs / s^2
The equation becomes:
d = 0.5 t^2
Now solving for d when t = 4:
d = 0.5 (4)^2
d = 0.5 * 16
<span>d = 8 furlongs</span>
<span>
</span>
<span>It traveled 8 furlongs for the first 4.0 seconds.</span>
see
below
Explanation:
refractive index = speed of light in vacuum / speed of light in medium
light travels at a speed of 3.0 x 10^8 m/s in vacuum
refractive index = 3.0 x 10^8 / 2.0 x 10^8
refractive index = 1.5
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