If a coin is dropped at a relatively low altitude, it's acceleration remains constant. However, if the coin is dropped at a very high altitude, air resistance will have a significant effect. The initial acceleration of the coin will be the greatest. As it falls down, air resistance will counteract the weight of the coin. So, the acceleration will decrease. Although the acceleration decreases, the coin still accelerates, that is why it falls faster. When the air resistance fully counters the weight of the coin, the acceleration will become zero and the coin will fall at a constant speed (terminal velocity). So, the answer should be, The acceleration decreases until it reaches 0. The closest answer is.
a. The acceleration decreases.
This assumes that the wave has velocity c (is light).
Answer:
The average speed of the earth in its orbit is 
Explanation:
The average distance between the Earth and the Sun is 
.
The average speed of the earth in its orbit can be found by the next equation :
(1)
Where r is the radius and T is the period.
In this case, the orbit of the Earth can be considered as a circle
(
) instead of an ellipse.
It takes 1 year to the Earth to make one revolution around the Sun. Therefore, its period will be 365.25 days.
Notice that to express the period in terms of seconds, the following is needed:
⇒ 
Then, equation 1 can be used:
Answer:
N
Explanation:
Using the formula you gave:
I am going to assume 2.1 metres per second and that we're rounding acceleration due to gravity to -10 metres per second squared. At the highest point, velocity is going to be 0. v= intial velocity + acceleration*time, sub in 0 for velocity, 2.1 for initial velocity and -10 for acceleration to get 0= 2.1-10t. Now solve for t. t=0.21 seconds.
