Throwing Up and Down
A person standing at the edge of a cliff throws one ball straight up and another ball straight down at the same initial speed. Neglecting air resistance, the ball to hit the ground below the cliff with the greater speed is the one initially thrown
A person standing at the edge of a cliff throws one ball straight up and another ball straight down at the same initial speed. Neglecting air resistance, the ball to hit the ground below the cliff with the greater speed is the one initially thrown
A) upward.
A) upward.
B) downward.
B) downward.
C) neither- they both hit at the same speed.
C) neither- they both hit at the same speed.
D) indeterminate.
D) indeterminate.
Solution: C. Using the formula vfy2 = viy2 + 2ayΔy, the final velocity can be solved as vfy = √(viy2 + 2ay Δy). The minus sign in the initial velocity for the downward throw is cancelled by the square. The acceleration and displacement are the same.
Solution: C. Using the formula vfy2 = viy2 + 2ayΔy, the final velocity can be solved as vfy = √(viy2 + 2ay Δy). The minus sign in the initial velocity for the downward throw is cancelled by the square. The acceleration and displacement are the same.