This is true since all matter contains some form of energy even just moving electrons and friction count as energy
Answer:
v = 0.6c = 1.8 x 10⁸ m/s
Explanation:
From Einstein's theory of relativity, we know that the length of an object contracts while traveling at a speed relative to speed of light. The contraction is according to following equation:

where,
L = Relative Length
L₀ = Rest Length
According to given:
L = 0.8 L₀
c = speed of light = 3 x 10⁸ m/s
v = relative speed of train = ?
Therefore,

squaring on both sides:

taking square root on both sides:
<u>v = 0.6c = 1.8 x 10⁸ m/s</u>
Answer:
final equilibrium temperature is 65.02 ◦C
Explanation:
Given data
milk = 12 g
temp milk = 7◦C
coffee = 175 g
coffee temp = 69◦C
to find out
final equilibrium temperature
solution
we apply here equilibrium condition i.e m c ΔT
milk mass × c × ΔT = coffee mass × c × ΔT
12 × 1 × (T- 7) = 175 × 1 × ( 69- T)
12T - 84 = 12075 - 175 T
187 T = 12159
T = 65.02
so final equilibrium temperature is 65.02 ◦C
Period = 6 seconds and
.
<u>Explanation:</u>
We have , the motion of a swing that requires 6 seconds to complete one cycle. Period is the amount of time needed to complete one oscillation . And in question it's given that 6 seconds is needed to complete one cycle. Hence ,Period of the motion of a swing is 6 seconds . Frequency is the number of vibrations produced per second and is calculated with the formula of
. SI unit of frequency is Hertz or Hz. We know that time period is 6 seconds so frequency =
⇒ 
⇒ 
⇒ 
Therefore , Period = 6 seconds and
.