Balloon dropping a sandbag (projectile motion)
publish date: 2022/08/04 05:33:00 GMT+10
volume_muteA balloon is high enough that the sandbag hits the ground 2 seconds after it is released. At that time the forward speed of the sandbag is still 12 m/s. Its downward speed is now 19.6 m/s.
This drawing uses a scale of cm to represent m/s. The arrow that shows the total is cm long, so the total velocity is m/s.
Correct Answer
Explanation
You can calculate the length of the line for the total velocity based on right-angled triangle
where the sum of squares of the two sides of the right angle = the square of the opposite line
a2 + b2 = c2
Let's assume the balloon velocity vector is a, and sandbag velocity vector is b, then the total velocity (cm) is = 42 + 6.52 = √58.25 = 7.6
since every every 1 cm = 3 m/s, the total velocity in (m/s) = 3 * 7.6 = 23 m/s
Reference
Basic Physics: A Self-Teaching Guide