Answer:
B, C and D are true.
<h3>Explanation:</h3>
A is false because they appear a pale reddish colour not purple.
Answer:
Force, F = 500 N
Explanation:
Given that,
Power expanded, P = 1000 W
Distance moved by piano, d = 10 m
Time taken, t = 5 s
To find,
The force exerted by the person
Solution,
The rate at which the work is being done is called power delivered. Its formula is given by:

W is the work done, W = F × d

On rearranging the above formula to find F as :


F = 500 N
Therefore, the force exerted on the person is 500 N. Hence, this is the required solution.
Answer:
Phase contrast microscope
Explanation:
It is used for viewing biological structures not visible under the microscope. It is used for viewing microrganisms live
<em></em>Your answer is :<em>
A.
</em>
Groundwater.<em>
</em>