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.
Answer:
v₂ = 176.24 m/s
Explanation:
given,
angle of projectile = 45°
speed = v₁ = 150 m/s
for second trail
speed = v₂ = ?
angle of projectile = 37°
maximum height attained formula,

now,


now, equating both the equations


v₂² = 31061.79
v₂ = 176.24 m/s
velocity of projectile would be equal to v₂ = 176.24 m/s
Answer:
a dog walking or their phone rings or heard a neighbor talking to them
Answer:
2 seconds
Explanation:
The frequency of a wave is related to its wavelength and speed by the equation

where
f is the frequency
v is the speed of the wave
is the wavelength
For the wave in this problem,
v = 2 m/s

So the frequency is

The period of a wave is equal to the reciprocal of the frequency, so for this wave:

This means that the wave takes 4 seconds to complete one full cycle.
Therefore, the time taken for the wave to go from a point with displacement +A to a point with displacement -A is half the period, therefore for this wave:

If the ground is flat, and both bullets are released at the same time from the same height, then they both hit the ground at the same time.
The horizontal motion of the one from the gun has no effect on its vertical motion.