Question

A projectile is thrown with initial velocity $v_{0}$ and angle $30^{\circ}$ with the horizontal. If it remains in the air for $1\, s$, what was its initial velocity?

• A. 19.6 m/s
• B. 9.8 m/s
• C. 4.9 m/s
• D. 1 m/s

Answer 1

Answer: (B)

9.8 m/s

Answer 2

Time of flight $T=\frac{2 u \sin \theta}{g}$
Given, $u=v_{0},\, T=1\, s,$
$\theta=30^{\circ}, g=9.8\, m / s ^{2}$
$v_{0}=u=g=9.8\, m / s$