Cells undergo cell division ( creates more cells to replace dead cells )
Answer:

Given:
Radius of curvature (R) of a spherical mirror = 20
To Find:
Focal length (f)
Explanation:
Formula:

Substituting value of R in the equation:



Answer: The end point of a spring oscillates with a period of 2.0 s when a block with mass m is attached to it. When this mass is increased by 2.0 kg, the period is found to be 3.0 s. Then the mass m is 0.625kg.
Explanation: To find the answer, we need to know more about the simple harmonic motion.
<h3>
What is simple harmonic motion?</h3>
- A particle is said to execute SHM, if it moves to and fro about the mean position under the action of restoring force.
- We have the equation of time period of a SHM as,

- Where, m is the mass of the body and k is the spring constant.
<h3>How to solve the problem?</h3>

- We have to find the value of m,


Thus, we can conclude that, the mass m will be 0.625kg.
Learn more about simple harmonic motion here:
brainly.com/question/28045110
#SPJ4
<span>Place a test charge in the middle. It is 2cm away from each charge.
The electric field E= F/Q where F is the force at the point and Q is the charge causing the force in this point.
The test charge will have zero net force on it. The left 30uC charge will push it to the right and the right 30uC charge will push it to the left. The left and right force will equal each other and cancel each other out.
THIS IS A TRICK QUESTION.
THe electric field exactly midway between them = 0/Q = 0.
But if the point moves even slightly you need the following formula
F= (1/4Piε)(Q1Q2/D^2)
Assume your test charge is positive and make sure you remember two positive charges repel, two unlike charges attract. Draw the forces on the test charge out as vectors and find the magnetude of the force, then divide by the total charge to to find the electric field strength:)</span>
Answer:
Explained below:
Explanation:
Water quality is determined in terms of the physical, chemical and biological content of water. The quality of water of lakes and rivers variates with the seasons and also geographic areas, still in the absence of pollution. There are so many factors which affect water quality are as follows :
Pesticides
Temperature
Runoff
Sedimentation
Erosion
pH
Dissolved oxygen
Pesticides
Litter and rubbish
Decayed organic materials
Toxic and hazardous substances
Oils, grease, and other chemicals