Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

interest to assist the presenter), and the presenter receives twice this score (

ID: 1774247 • Letter: I

Question

interest to assist the presenter), and the presenter receives twice this score (so it is in the presenter's interest to be as clear and careful as possible). Presenters will be rotated within the assigned lab groups so that each student has the opportunity to serve as presenter at least three times. These scores will also be added, and divided by the total number of available presentation points (typically 120), that fraction will determine 20 points of the overall lab grade. 5. Group B m/s at the same instant that a 20 gram A 30 gram dart is shot directly vertically upward at 9.0 cork sphere is dropped from 3.0 m above the dart. Find the velocity of the dart-cork system immediately after the collision. Assume the collision is exactly head-on, the dart sticks in the cork, and that air resistance is negligible

Explanation / Answer

Let the collide after time t, their positions above ground will also be equal:

ut - 0.5gt^2 = h0 - 0.5gt^2

ut = h0

9t = 3

t = 1/3 s

now we got the time, we can find the velocities just before collision

u1 = u - gt = 9 - 9.8/3 = 5.7333 m/s

u2 = -gt = -9.8/3 = -3.2667 m/s

momentum will be conserved for a short time, m1u1 + m2u2 = (m1+m2)v

0.030*5.7333 + 0.020*-3.2667 = (0.020+0.030) v

0.106667 = 0.050 v

v = 0.106667/0.050

= 2.133 m/s answer