Question

A projectile thrown with an initial velocity of 10 ms$^-1$ at an angle $\alpha$ with the horizontal, has a range of 5 m. Taking g = 10 ms$^-2$and neglecting air resistance, what will be the estimated value of $\alpha$ ?

• A. 15?
• B. 30?
• C. 45?
• D. 75?

Answer 1

Answer: (D)

75?

Answer 2

$5=\frac{100 sin\left(2\theta\right)}{10} \therefore sin\left(2\theta\right) =\frac{1}{2} \therefore\theta =15?, 75?$