Answer: 500 s
Explanation:
Speed
is defined as a relation between the distance
and time
:

Where:
is the speed of light in vacuum
is the distance between the Earth and Sun
is the time it takes to the light to travel the distance
Isolating
:


Finally:

<h2>Answer: True
</h2>
The <u>Doppler effect</u> refers to the change in a wave perceived frequency when the emitter of the waves, and the receiver (or observer in the case of light) move relative to each other.
In other words, it is the variation of the frequency of a wave due to the relative movement of the source of the wave with respect to its receiver.
It should be noted that this effect bears its name in honor of the Austrian physicist <u>Christian Andreas Doppler</u>, who in 1842 proposed the existence of this effect for the case of light in the stars. Another important aspect is that the effect occurs in all waves (including light and sound). However, it is more noticeable to humans with sound waves.
Answer:
The car traveled the distance before stopping is 90 m.
Explanation:
Given that,
Mass of automobile = 2000 kg
speed = 30 m/s
Braking force = 10000 N
For, The acceleration is
Using newton's formula

Where, f = force
m= mass
a = acceleration
Put the value of F and m into the formula

Negative sing shows the braking force.
It shows the direction of force is opposite of the motion.


For the distance,
Using third equation of motion

Where, v= final velocity
u = initial velocity
a = acceleration
s = stopping distance of car
Put the value in the equation


Hence, The car traveled the distance before stopping is 90 m.
If there is no current in the wire .....the direction of magnetic field remains unchanged
Mechanical energy = potential energy + kinetic energy
The ball is on the ground so it has no potential energy. that's all i know.