They are the element symbols. Too many to list here, look up a periodic table.
Answer:
(b) The average speeds are the same, but the average velocities are different
Explanation:
Given,
- Distance traveled in the east direction = 1500 m
- time take = t = 2 sec
- Distance traveled in the north direction = 1500 m
- time taken = t = 2 sec,
Hence the distance traveled in both the direction is the same of 1500 m in the same time of interval t = 2 sec,
We know that the average speed is the ratio of the total distance traveled and the total time is taken. And the speed does not depends upon the direction of the distance traveled. Thus in both cases, average speeds are the same
But in case of the average velocity, average velocity is equal to the ration of the total displacement and the total time is taken, and also it depends upon the direction of the displacement because the velocity is a vector quantity.
In both the magnitude of the case of the velocities are the same but the direction of the velocities is different, due to this the average velocities in both the cases are different.
Therefore the option (b) the average speeds are the same and the average velocities are different, is correct.
1) 234 s, 6.18 km
The position of the car at time t is described as
where
is the velocity of the car
The position of the head of the train instead is given by
where
d = 1.30 km is the initial distance between the car and the head of the train
is the velocity of the train
The car overtakes the train when
Substituting and solving for t,
And the distance travelled by the car is
2) 27.5 s, 0.72 km
In this case, the train is travelling in opposite direction, so we can write
Again, we can use the same equation as before
And solving for t, we find
And the distance travelled by the car is
