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:

Our solar system formed from a huge cloud of dust and gas called a
c. solar nebula
Based on the nebular hypothesis, our solar system formed from hydrogen gas and interstellar dust. The gas and the dust contracted and formed the early stage of the sun.
Answer:

Explanation:
The acceleration due to gravity on the surface of the Earth is given by:

where
G is the gravitational constant
M is the mass of the Earth
R is the radius of the Earth
Here we want to find the new Earth radius R' for which the gravitational acceleration at the surface, g', would be 3 times the current value of g:

So we would have

Solving the equation for R', we find

No clue. bye. and gold luck!
I. the type of wave ... electromagnetic or mechanical
(II. amplitude doesn't influence the speed of any wave)
III. the medium in which the wave travels ... completely determines the wave speed