a person drops a ball (a) out a window and also throws a ball (b) down at the same time with an initial…
a person drops a ball (a) out a window and also throws a ball (b) down at the same time with an initial velocity of 10 m/s.\na) what is the velocity of a after 2 seconds?\nb) how far has a fallen in 2 seconds?\nc) if ball b has a velocity of 40 m/s, how long ago was it thrown downward?
Answer
Explanation:
Step1: Find velocity of A
Use the formula (v = v_0+at). For ball A, (v_0 = 0\ m/s) (dropped), (a = g= 9.8\ m/s^2), (t = 2\ s). (v=0 + 9.8\times2)
Step2: Find distance fallen by A
Use the formula (s=v_0t+\frac{1}{2}at^2). For ball A, (v_0 = 0\ m/s), (a = g = 9.8\ m/s^2), (t = 2\ s). (s=0\times2+\frac{1}{2}\times9.8\times2^{2})
Step3: Find time for ball B
Use the formula (v = v_0+at). For ball B, (v = 40\ m/s), (v_0 = 10\ m/s), (a = g=9.8\ m/s^2). (40=10 + 9.8t), then solve for (t): (9.8t=40 - 10), (t=\frac{30}{9.8})
Answer:
a) (19.6\ m/s) b) (19.6\ m) c) (\approx3.06\ s)