Answer:
1.69515 seconds
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration

The distance between the traffic and the car after braking is 120-64.06 = 55.94 m
Time = Distance / Speed

The reaction time cannot be more than 1.69515 seconds
Answer:
The force exerted on an electron is 
Explanation:
Given that,
Charge = 3 μC
Radius a=1 m
Distance = 5 m
We need to calculate the electric field at any point on the axis of a charged ring
Using formula of electric field


Put the value into the formula


Using formula of electric field again

Put the value into the formula


We need to calculate the resultant electric field
Using formula of electric field

Put the value into the formula


We need to calculate the force exerted on an electron
Using formula of electric field


Put the value into the formula


Hence, The force exerted on an electron is 
Answer:
600m
Explanation:
30×20 at a constant speed is 600m.
Answer: a network of several radio telescopes wired together
Explanation:
A radio interferometer combines signals of several radio telescopes which are used in astronomical observations simultaneously to simulate a discretely-sampled single telescope of very large aperture
Interferometer, an instrument that uses the interference patterns formed by waves to measure certain characteristics of the waves themselves or of materials that reflect, refract, or transmit the waves. Interferometers can also be used to make precise measurements of distance.