Light travels faster than sound ,because sound can only travel waves.
By using third law of equation of motion, the final velocity V of the rubber puck is 8.5 m/s
Given that a hockey player hits a rubber puck from one side of the rink to the other. The parameters given are:
mass m = 0.170 kg
initial speed u = 6 m/s.
Distance covered s = 61 m
To calculate how fast the puck is moving when it hits the far wall means we are to calculate final speed V
To do this, let us first calculate the kinetic energy at which the ball move.
K.E = 1/2m
K.E = 1/2 x 0.17 x 
K.E = 3.06 J
The work done on the ball is equal to the kinetic energy. That is,
W = K.E
But work done = Force x distance
F x S = K.E
F x 61 = 3.06
F = 3.06/61
F = 0.05 N
From here, we can calculate the acceleration of the ball from Newton second law
F = ma
0.05 = 0.17a
a = 0.05/0.17
a = 0.3 m/
To calculate the final velocity, let us use third equation of motion.
=
+ 2as
=
+ 2 x 0.3 x 61
= 36 + 36
= 72
V = 
V = 8.485 m/s
Therefore, the puck is moving at the rate of 8.5 m/s (approximately) when it hits the far wall.
Learn more about dynamics here: brainly.com/question/402617
The scientific revolution is a concept which explains how the developments of science (biology, chemistry, physics and etc.) changed the way we (society) think about nature. I hope this helps! :)
Distance = speed X time
In this example, the speed of the airplane = 840km. The time (that the question is asking)is how far can it travel in 1 hour.
So just plug in your numbers.
Distance = 840km X 1 hour = 840km/hour or 840km for short.
Answer: Option B
The wavelength for a radio wave with a frequency of 2 × 10⁴ Hz is
1.5 × 10⁴ m.
Explanation:
Wavelength is the measure of distance between two successive crests or troughs in a standing wave. Also wavelength can be measured as the ratio of velocity of light to frequency. It is like this because wavelength is inversely proportional to the frequency.

As c = 3 × 10⁸ m/s and the frequency is 2 × 10⁴ Hz, then the wavelength will be

So, the wavelength for a radio wave with a frequency of 2 × 10⁴ Hz is
1.5 × 10⁴ m.