The distance between the charges is 13.86 X 10⁴m
<u>Explanation:</u>
Given:
Force, F = 1.2N
Charge, q₁ = 1.602 X 10⁻¹⁹ C
k = 8.987 X 10⁹ Nm²/C²
Distance, d = ?
According to Coulomb's law:

Substituting the value in the formula we get:

Therefore, the distance between the charges is 13.86 X 10⁴m
Explanation:
This is a good example of Doppler effect
Given
Source velocity Vs=20m/s
Apparent frequency Fa= 5.2 Hz
Recall speed of sound V=340m/s
The frequency of the horn Fh=?
But mathematically Fh=(V-Vs/V)*Fa
(340-20)/340*5.2=4.89Hz
Answer:

so gravity will be same as that of surface of earth
Explanation:
As we know that the acceleration due to gravity is given as

here we have


we know that for earth we have

now if the radius and mass is given as above



so gravity will be same as that of surface of earth
Answer:
3.9 m/s
Explanation:
We are given that
Mass of car,m=
Initial velocity,u=0
Distance,s=5.9 m

Average friction force,f=
We have to find the speed of the car at the bottom of the driveway.
Net force,
Where 
Acceleration,


v=3.9 m/s