Question

Question 8 (1 point) A ball rolls off a table that is 1.17 m high with a horizontal velocity of 1.34 m/s. What are the components of the final velocity when the ball hits the floor? a) Vx = 4.79 m/s ; Vfy = - 1.34 m/s b) vx= 1.34 m/s ; Vfy = - 4.79 m/s Oc) vx = 1.34 m/s ; Vfy = - 3.65 m/s O d) vx = 2.68 m/s ; Vfy = - 4.79 m/s Question 9 (1 point) A football is kicked on a level field with an initial velocity of 25.0 m/s with an angle of elevation of 40.0°. For how much time is the ball in the air and what is the maximum height reached by the ball? a) t = 1.64 s; hmax = 13.2 m Ob) t = 2.76 s; hmax = 25.0 m Oc) t = 1.64 s; hmax = 26,4 m Od) t = 3.28 s ; max = 13.2 m

Answer 1

(8) The horizontal velocity of the ball will not change, hence we can say that the x component of the velocity will be 1.34 m/s only. The vertical component of the velocity can be calculated as, (the initial vertical velocity is 0)

$v = \sqrt{2 gh}$

Substituting values we can write,

v= 2(9.81)(1.17) = 4.79m/s

Hence the appropriate answer is (b).