Problem 4-11 - Free fall - Part 10 - (C)
A ball is thrown from a balloon with an initial unknown velocity. The ball accelerates at \(9.80\;m/s^2\) downward for \(2.00\; s\), at which time its instantaneous velocity is \(24.0\; m/s\) at an angle of \(45.0^\circ\) below the horizontal. Determine the magnitude and direction of the initial velocity.
Accumulated Solution
\(v = v_0 + at\)
\(v_x = v_{0x} + a_xt \\ v_y = v_{0y} + a_yt \\ a_x = 0 \\ a_y = g \\ v_x = v_{0x} \\ v_y = v_{0y} + 9.8t \\ v_x = 24 \cos45 = 17.0\; m/s \\ v_y = 24 \cos45 = 17.0\; m/s \\ v_{0x} = v_{0x} = 17.0 \; m/s \\ v_{0y} = -2.6 \; m/s\)
Correct.
\(v_0 = [(17.0)^2 + (-2.6)^2]^{1/2} = 17.2\; m/s\)
Which arrow represents the initial velocity?
