Question

The range of projectile when launched at an angle of ${15}^{\circ }$ with the horizontal is $1.5km$. What is the range of the projectile when launched at an angle ${45}^{\circ }$ to the horizontal

• A. $1.5km$
• B. $3.0km$
• C. $6.3km$
• D. $0.75km$

Answer 1

Answer: (B)

$3.0km$

Here in first case, $R_1=1.5,\theta =15$

$R_1=\frac{u^2\sin (2\times 15)}{g}\Rightarrow 1.5=\frac{u^2}{2g}$

$\Rightarrow \frac{u^2}{g}=3$

Now, for second case,

$R_2=\frac{u^2\sin (2\times 45)}{g}\Rightarrow R_2=\frac{u^2}{2g}=3km$