Seed 182

course phy 201

for some reason the seed question 18.2 seemed to not be complete. i received the questions but the page did not go past that, therefore i could not copy and paste the work into that form and submit. i am submitting the questions that i saw through this submit work form and hope that it has not caused any confusion. thank you.

A child in a car tosses a ball upward so that after release it requires 1/2 second to rise and fall back into the child's hand at the same height from which it was released. The car is traveling at a constant speed of 10 meters / second in the horizontal direction. •Between release and catch, how far did the ball travel in the horizontal direction?

answer/question/discussion: v = ‘ds / ‘dt so therefore, ‘ds = v * ‘dt = 10 * .5 = 5 meters

• As observed by a passenger in the car, what was the path of the ball from its release until the instant it was caught?

answer/question/discussion: a parabolic form

from the frame of reference of the car the path would be straight up and down; from the side of the road it would be parabolic

• Sketch the path of the ball as observed by a line of people standing along the side of the road. Describe your sketch. What was shape of the path of the ball?

answer/question/discussion: it is a parabolic shape, going upward but at an angle until it reaches its maximum height, at which time it would level off a little, then begin to fall but continuing to move forward at an angle

• How fast was the ball moving in the vertical direction at the instant of release? At that instant, what is its velocity as observed by a line of people standing along the side of the road?

answer/question/discussion: I will be using the first half of the path of the ball, dividing the time by 2 and using vf = 0 m/s.

a = (vf - v0) / ‘dt so therefore, v0 = vf – a(‘dt)

v0 = 0 – (-9.8)(.25) = 2.45 m/s

• How high did the ball rise above its point of release before it began to fall back down?

answer/question/discussion: 2.45/2 = 1.225 m/s equals vAve

vAve = ‘ds / ‘dt so therefore, ‘ds = 1.225 * .25 = .306 meters

Good, but be sure to see my note about the path as observed from the car.