Answer:
C. 2.7 m/s
Explanation:
Consider the motion of the marble along the vertical direction
y = vertical displacement = height of tabletop = 1.0 m
a = acceleration = 9.8 m/s²
t = time taken to hit the floor = ?
v₀ = initial speed of the marble along vertical direction = 0 m/s
Using the equation
y = v₀ t + (0.5) a t²
1.0 = (0) t + (0.5) (9.8) t²
t = 0.45 s
Consider the motion of the marble along the horizontal direction :
v = speed with which the marble leaves the table
x = horizontal displacement = 1.2 m
t = 0.45 s
horizontal displacement is given as
x = v t
1.2 = v (0.45)
v = 2.7 m/s