Answer:
17.64 km/h
Explanation:
mass of car, m = 1000 kg
Kinetic energy of car, K = 1.2 x 10^4 J
Let the speed of car is v.
Use the formula for kinetic energy.

By substituting the values

v = 4.9 m/s
Now convert metre per second into km / h
We know that
1 km = 1000 m
1 h = 3600 second
So, 
v = 17.64 km/h
Thus, the reading of speedometer is 17.64 km/h.
There is no definite end to earths atmosphere, but technically the border between the outer space and earth gets thinner as you move up from the earths surface. The Karman line is the closest definition there is which describes the end of the earth's atmosphere, it is 100 km above earth's sea level at approximately 1.56 % of total earth's radius. This describes the boundary between the outer space and the atmosphere.
Answer:
145.52137 m/s
1.4 m
0.7 m
60.6339 Hz
121.2678 Hz
Explanation:
T = Tension = 120 N
= Linear density = 
m = Mass of wire = 6.8 g
L = Length of wire = 1.2 m
n = Number of loops
Velocity is given by

The speed of waves on the wire is 145.52137 m/s
Wavelength is given by

The wavelength of the waves that produces one-loop standing waves is 1.4 m

The wavelength of the waves that produces two-loop standing waves is 0.7 m
Frequency is given by

The frequency of the waves that produces one-loop standing waves is 60.6339 Hz

The frequency of the waves that produces two-loop standing waves is 121.2678 Hz
Light always travels in a straight line when going through a single medium, any substance through which a light wave can travel. In some mediums, such as air, light travels quickly. ... Heat, light and sound are similar to each other. They are forms of energy and they travel in waves.