The correct sentence is:
The taxi is moving with reference to A) Monument circle. For each leg of the trip, the taxi’s A) Average speed stays the same, but its B) Average velocity changes.
In fact, speed it is only the ratio between the distance traveled and the time taken - so it does not take into account the direction of motion. The speed in the first leg is
while the speed in the second leg is
so the speed stays the same.
However, the velocity also takes into account the direction of motion: in the first leg, the direction is east, while in the second leg, the direction is south, therefore the average velocity has changed, since the direction has changed.
Answer:
Yes, the velocity would also be zero.
Explanation:
Acceleration is the change in velocity over time, therefore, there has to be a change in velocity for something to accelerate. which means without acceleration, the object has no velocity.
It's a chemical change since it cannot be reversed and the saliva releases a new substance
Thank you for your question, what you say is true, the gravitational force exerted by the Earth on the Moon has to be equal to the centripetal force.
An interesting application of this principle is that it allows you to determine a relation between the period of an orbit and its size. Let us assume for simplicity the Moon's orbit as circular (it is not, but this is a good approximation for our purposes).
The gravitational acceleration that the Moon experience due to the gravitational attraction from the Earth is given by:
ag=G(MEarth+MMoon)/r2
Where G is the gravitational constant, M stands for mass, and r is the radius of the orbit. The centripetal acceleration is given by:
acentr=(4 pi2 r)/T2
Where T is the period. Since the two accelerations have to be equal, we obtain:
(4 pi2 r) /T2=G(MEarth+MMoon)/r2
Which implies:
r3/T2=G(MEarth+MMoon)/4 pi2=const.
This is the so-called third Kepler law, that states that the cube of the radius of the orbit is proportional to the square of the period.
This has interesting applications. In the Solar System, for example, if you know the period and the radius of one planet orbit, by knowing another planet's period you can determine its orbit radius. I hope that this answers your question.
