Question
please do 9and 10
-7 of a two-story house makes an angle of 330 with the honzontal. A ball rolling down the roof rolls (a) How long is the ball in the air? -/10 points off the edge at a speed of 5.6 m/s. The distance to the ground from that point is 7.0 m (b) How far from the base of the house does it land? (c) What is its velocity just before landing? (Let upward be the positive y-direction.) x-component y-component my's eBook 0 10 points You are watching your friend play hockey. In the course of the game, he strikes the puck in such a way that, when it is at its highest point, it just clears the surrounding 2.92 m high Plexiglas wall that is 13.2 m away. (Ignore any effects due to air resistance.) (a) Find the vertical component of its initial velocity m/s (b) Find the time it takes to reach the wall (c) Find the horizontal component of its initial velocity, and its initial speed and angle Vo ms eBook
Explanation / Answer
a)
y = y0 + vy0*t- 1/2*g*t^2
where y = 0 ; y0 = 7.0, vy0 = -5.6m/s*sin(33) = -3.05 m/s
So 4.9t^2 + 3.05t - 7.0 = 0 .
t = 0.9239
b) x = vx0*t = 5.6m/s*cos(33)*0.9239s = 4.339 m
c) vx = vx0 = 5.6m/s*cos(33) = 4.7 m/s
vy = vy0 - g*t = -3.05m/s- 9.8m/s^2*0.9239 s = -12.1 m/s
Please post the other question separately
