Answer:
Option b.
Step-by-step explanation:
We can easily solve this problem by using a graphing calculator or plotting tool.
The function is
h(t) = cos (t +1)
Please, see attached picture below.
By looking at the picture, we can tell that the amplitude is equal to 1
The function has a period of T = 2π
We can see there is no vertical shift.
It has a phase shift of +1. (Which moves the graph to the left)
Answer:
Option b.
Given that the subway stations are 930 m apart, the train have to be accerelated for half the distance and then decerelated for the rest of the distance.
Recall that the distance travelled by an object with an initial velocity, u, for a period of time, t, at an accereration, a, is given by
But, we assume that the train accelerates from rest, thus
The maximum speed is attained at half the center of the distance between subway stations (i.e. at distance = 465 m).
Thus, maximum speed = distance / time = 465 / 23.12 = 20.11 m/s.
When you divide 1722 by 6 you get 287 so it's not a repeating number so if you estimate 287 to 290 then you get 1740 so your answer is 287.
Cutting her time by 50% means reducing her time by half. Half of 45 seconds is 22.5 seconds. Therefore, to make the team, she must run a lap in 22.5 seconds.
