100 is the correct answer
Step-by-step explanation:
h = -490t² + 1470t
When h = 980:
980 = -490t² + 1470t
Simplifying:
0 = -490t² + 1470t - 980
0 = t² - 3t + 2
Factoring:
0 = (t - 1) (t - 2)
t = 1, 2
There are two solutions because the rocket first reaches the height of 980 cm as it's going up at 1 second, then it reaches that height again as it's coming down at 2 seconds.
Answer:
65 miles per hour
Step-by-step explanation:
r = d/t
1 : 5 = 0.2
r = 13 : 0.2 = 65
Answer:.03
Step-by-step explanation:
