Index of refraction of a substance =
(speed of light in vacuum) / (speed of light in the substance)
Index in quartz = (2.9979 x 10⁸ m/s) / (2.0567 x 10⁸ m/s)
<em>Index = 1.4576 </em> (no units)
Answer:
The expression of x=4t+2t^2
Where x is distance and t=time
What is displecement?
Answer:

Explanation:
The amount of work done by Devin when moving the lawn is given by:

where
F is the average force applied
d is the displacement of the lawn
is the angle between the direction of the force and the displacement
Assuming that Devin moves the lawn by applying a force parallel to the displacement, we have:
F = 75 N
d = 1.5 km = 1500 m

Therefore, the work done is
