Students in a lab measure the speed of a steel ball launched horizontally from a
ID: 1426166 • Letter: S
Question
Students in a lab measure the speed of a steel ball launched horizontally from a tabletop to be (v). The table-top is distance (y) above the floor. They place a tall tin coffee can of height (0.1 y)on the floor to catch the ball.
Part A
Find a horizontal distance from the base of the table the can should be placed.
Express your answer in terms of the variables ( exttip{v}{v}), ( exttip{y}{y}), and appropriate constants.
Part B
If the ball leaves the tabletop at a speed of 4.8 ({ m m/s}) , the tabletop is 1.6 ({ m m}) above the floor, and the can is 0.15 ({ m m}) tall, find a horizontal distance from the base of the table that the center of the can should be placed.
Express your answer to two significant figures and include the appropriate units.
Explanation / Answer
along vertical
inital velocity voy = 0
acceleration ay = -g = -9.8 m/s^2
displacement dy = yf - yi
from equation of motion
dy = voy*t + 0.5*ay*t^2
t = sqrt(2*dy/ay)
along horizantal
X = vox*t
x = v*sqrt(2*(0.1y-y)/ay
x = v*sqrt(2*(y-0.1y)/g)
++++++++++++++++++++
part B
x = 4.8*sqrt(2*(1.6-0.15)/9.8)
x = 2.61 m <<------------answer