<span>The following which is not an example of work is </span>C. holding a tray in the cafeteria line because <span>if force displaces an object it should work. I think it's clear and I am pretty sure this answer will help you.</span>
Answer: 0.067 s
Explanation:s = Ut + 1/2at^2
0.6 = 9t + 0.5 *10 *t^2
Where a = g =10m/s/s
Solving the quadratic equation
5t^2 + 9t - 0.6=0,
t= 0.067 s and - 1.7 s
Of which 0.067 s is a valid time
<h2>Answer:</h2>
The refractive index is 1.66
<h2>Explanation:</h2>
The speed of light in a transparent medium is 0.6 times that of its speed in vacuum
.
Refractive index of medium = speed of light in vacuum / speed of light in medium
So
RI = 1/0.6 = 5/3 or 1.66
The acceleration of the car,

Here, v is final velocity, u is initial velocity and t is time taken by the car.
Given
,
and 
Therefore, from above equation
.
Here, negative sign shows deceleration of a car.
Thus the the magnitude of car acceleration is
.