The line from ‘A’ to ‘B’ makes an angle of 30° with the horizontal. The initial velocity of the object is: (take g = 10 m/s²)

Question

G1 Physics · Accepted Answer

As printed, the question gives only the direction of displacement AB and g; that is not enough to determine a unique initial speed. The source key marks option A, 15√3 m/s. This value follows if the missing flight time is 3 s (the same setup as the earlier Concept Application): tan30° = (½gt²)/(ut), so u = gt/(2tan30°) = 15√3 m/s. The source statement is therefore incomplete as printed.