Answer:
Part a)
[tex]d = 1.2 m[/tex]
Part b)
[tex]\Delta y = 0.78 m[/tex]
Part c)
[tex]v = 4.9 m/s[/tex]
Explanation:
Part a)
Speed of the ball = 3.0 m/s
time taken by the ball to hit the floor = 0.40 s
so the total distance moved by the ball in horizontal direction is given as
[tex]d = velocity \times time[/tex]
[tex]d = (3.0)\times 0.40[/tex]
[tex]d = 1.2 m[/tex]
Part b)
The height of the desk is same as the displacement of ball in vertical direction during its free fall
so it is given as
[tex]\Delta y = v_y t + \frac{1}{2}at^2[/tex]
[tex]\Delta y = 0 + \frac{1}{2}(9.81)(0.40)^2[/tex]
[tex]\Delta y = 0.78 m[/tex]
Part c)
In x direction the velocity of ball will remains the same
[tex]v_x = 3.0 m/s[/tex]
in Y direction the velocity of ball is given as
[tex]v_y = v_i + at[/tex]
[tex]v_y = 0 + (9.81)(0.40)[/tex]
[tex]v_y = 3.92 m/s[/tex]
so the speed of the ball is given as
[tex]v = \sqrt{v_x^2 + v_y^2}[/tex]
[tex]v = \sqrt{3.92^2 + 3.0^2}[/tex]
[tex]v = 4.9 m/s[/tex]
