Undergrad physics problem, please help!?
A red ball is dropped from a height of 30.2m. At the same time, a blue ball is launched straight up from the ground with an initial speed of 13.6 m/s.
a. What is the maximum height reached by the blue ball?
b. When does the blue ball reach this height?
c. How far above the blue ball is the red ball at this time?
d.How fast is the red ball moving at this time?
e. When do the ball collide?
f. Where do they collide?
g. How fast is each ball moving when they collide?
I have been working on this problem all day, and I hope that I have figured out some solutions but want to be sure I am on the right track, as there are many other problems like this that I need to solve. Thanks so much for any help!
More Questions From This User See All
Answers & Comments
Verified answer
a. Use v² = u² +2as with v = 0, u = 13.6, a = -9.8. We get 0 = 13.6² - 2 x 9.8s, giving s = 9.437m.
b. Use v = u + at with v = 0, u = 13.6, a = -9.8. We get 0 = 13.6 - 9.8t, giving t = 1.388s
c. For the red ball s(1) = 0.5 x 9.8t², for the blue ball s(2) = 13.6t - 0.5 x 9.8t², |s(1) - s(2)| = |13.6t - 9.8t²| = 0.
d. Use v = u + at with u = 0, a =9.8, t = 1.388. We get v = 9.8 x 1.388 = 1.36m/s.
e. They collide at t = 1.388s.
f. Use s = ut + 0.5at² with u = 0, a = 9.8, t = 1.388. We get s = 0.5 x 9.8 x 1.388² = 9.44m from the top.
g. The red ball is moving at 1.36m/s when they collide/ For the blue ball use v = u + at with u = 13.6, a = -9.8, t = 1.388. We get v = 13.6 - 0.5 x 9.8 x 1.388 = 6.8m/s.