Answer:
0.45 miles
Explanation:
since, car will be running on the edge of track, distance covered in one lap by car will be equal to circumference of track.\
we will use value of pi as 22/7
Circumference for any circular shape is given by 

Hence, in one lap
distance will be covered
in 7 laps
distance will be covered.
but is given that 7 laps should be equal to 10 miles
so 10 miles will be equal to 

Thus, diameter of track will be 0.45 miles to meet the requirement.
The correct answer should be D. copper
Nickel, cobalt, and iron, produce magnetic fields when electrified while copper does not.
If an object changes the speed of <u>direction</u>, its velocity also changes. Any change in <u>velocity</u> results in acceleration.
Hope that helps!
If both waves have the same wavelength, then the amplitude of
their sum could be anything between 1 cm and 9 cm, depending
on the phase angle between them.
If the waves have different wavelengths, then the resultant is a beat
with an amplitude of 9 cm.
B is the answer to your question