Answer:
7500 m
Explanation:
The radar emits an electromagnetic wave that travels towards the object and then it is reflected back to the radar.
We can call L the distance between the radar and the object; this means that the electromagnetic wave travels twice this distance, so
d = 2L
In a time of

Electromagnetic waves travel in a vacuum at the speed of light, which is equal to

Since the electromagnetic wave travels with constant speed, we can use the equation for uniform motion ,so:
(1)
where


, where L is the distance between the radar and the object
Re-arranging eq(1) and substituting, we find L:

Explanation:
The given data is as follows.
distance (r) = 1.67 m
= 1 C
It is known that formula for electric force between two charges is as follows.
F = 
Hence, putting the given values into the above formula as follows.

= 
As it is given that mass of Falcon Heavy rocket is 1421. Therefore, weight of 1 Falcon rocket is as follows.
weight of 1 falcon rocket =
Therefore, number of falcon rockets will be calculated as follows.
No. of falcon rockets = 
=
= 2318.9 falcons
Thus, we can conclude that force between the two point charges above is equal to the weight of 2318.9 Falcon Heavy rockets.
A. All living things and objects
This question is true because it just is
Answer:
1 and 2
Explanation:
It is given that, force exerted by air is negligible in any way.
Also, it is given that channel is in the shape of a segment of a circle with its center at O.
When it is within the frictionless channel at position 'Q',
A gravity exerts force on the ball in the downward direction. On the other hand, the channel pointing from Q to O also exerts a force on the ball.
However, there is no any force in the direction of motion. On the other hand, he channel pointing from O to Q does not exert a force on the ball.