Answer:
d) shortening the string
Explanation:
Time period of a pendulum clock is dependent on two factors namely:length and acceleration due to gravity.
When a clock loses time, the time period of the pendulum clock increases.
This however can be corrected by decreasing the length of the pendulum.The time period of the pendulum clock is not dependent on the mass of the bob. The time period of the pendulum clock can be corrected only by changing the length of the pendulum string.
(a) The work done by the force applied by the tractor is 79,968.47 J.
(b) The work done by the frictional force on the tractor is 55,977.93 J.
(c) The total work done by all the forces is 23,990.54 J.
<h3>
Work done by the applied force</h3>
The work done by the force applied by the tractor is calculated as follows;
W = Fd cosθ
W = (5000 x 20) x cos(36.9)
W = 79,968.47 J
<h3>Work done by frictional force</h3>
W = Ffd cosθ
W = (3500 x 20) x cos(36.9)
W = 55,977.93 J
<h3>Net work done by all the forces on the tractor</h3>
W(net) = work done by applied force - work done by friction force
W(net) = 79,968.47 J - 55,977.93 J
W(net) = 23,990.54 J
Learn more about work done here: brainly.com/question/25573309
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Answer:
(a) 
(b) 
(c)
(d)
Solution:
As per the question:
Refractive index of medium 1, 
Angle of refraction for medium 1, 
Angle of refraction for medium 2, 
Now,
(a) The expression for the refractive index of medium 2 is given by using Snell's law:

where
= Refractive Index of medium 2
Now,

(b) The refractive index of medium 2 can be calculated by using the expression in part (a) as:


(c) To calculate the velocity of light in medium 1:
We know that:
Thus for medium 1
(d) To calculate the velocity of light in medium 2:
For medium 2:
Answer:
c
Explanation:
it's the only one that makes sense