Answer: because she is pedalling at her maximum speed produced by the maximum force applied. At constant speed, acceleration is equal to zero.
Explanation:
Pedalling of bicycle involves application of force. The force applied produces circular motion to the tires which eventually transform into linear speed.
V = wr
Where V = linear speed
W = angular speed
r = radius.
Change in speed V will lead to acceleration or deceleration depending on increase or decrease in speed.
If she stops accelerating, then, she must have applied force that makes her pedalling at maximum speed. She is also maintaining this uniform (constant ) speed. After reaching her maximum speed.
At constant speed, acceleration = 0
Base on this explanation, even though she is still pedalling as fast as she can, which at constant speed, she will stop accelerating and her speed reaches a maximum value because she is pedalling at her applied maximum force.
Answer:
8.4 m/s
Explanation:
The toy completes 10 circle in 30 seconds. So its frequency of revolution is
The periof of revolution is the reciprocal of the frequency, so
The radius of the circular path is
r = 4.0 m
So the total distance covered by the toy in one circle is the length of the circumference:
And so the average speed is
Answer;
- June 21
At 45 degrees latitude, the angle of the noon sun is lowest and the length of daylight is shortest on June 21.
Explanation;
-On June 21 you will note that the Northern Hemisphere is pitched toward the Sun. This means that the Sun's vertical ray is striking the Earth at the Tropic of Cancer (23.5 degrees N).
-Days tend to get longer in the northern hemisphere from December 21 to June 21, and then grow shorter from June 21 to December 21. The June solstice is the summer solstice in the Northern Hemisphere and the winter solstice in the Southern Hemisphere. The date varies between June 20 and June 22, depending on the year, and the local time zone.
Answer:
O²⁻
Explanation:
Number of protons = 8
Number of neutrons = 9
Number of electrons = 10
What type of atom or ion is it = ?
Solution:
Protons are the positively charged particle in an atom
Neutrons do not carry any charges
Electrons are negatively charged particles
For this atom, the number of protons helps to identify what specie it is; so this is an oxygen atom.
Now,
Charge = Number of protons - Number of electrons
Charge = 8 - 10 = -2
The charge on the atom is -2 and so it is an oxygen ion with -2 charge
The ion is O²⁻
