Get Answers to all your Questions

header-bg qa

The distances and heights of two projectiles fired at the same initial velocity at angles  42  and to  48  the

horizontal is respectively R_1,R_2 and H_1,\ H_2

Option: 1

R_1>R_2\ and\ H_1=H_2


Option: 2

R_1=R_2\ and\ H_1<H_2


Option: 3

R_1<R_2\ and\ H_1<H_2


Option: 4

R_1=R_2\ and\ H_1=H_2


Answers (1)

best_answer

Answer: (B) R_1=R_2\ and\ H_1<H_2                  

Explanation:

Here are two projectiles launched at angles 42^{\circ} and 48^{\circ} with the same initial speed.
As we know the expression for projectile range,
Range\ =\frac{u^2 sin 2\theta}{g}        
At

\theta_1=42^{\circ}

Range, R_1=\frac{u^2 \sin2(42^{\circ})}{g}                   

At,
\theta_2=48^{\circ}
R_2=\frac{u^2sin2\left (48^{\circ} \right )}{g}                                       
Therefore, R_1=R_2                                       

Now, we know the expression for the height of the projectile.

H_{max}=\frac{u^2 sin\theta}{2g}                                   
For

42^{\circ}
H_{max}=H_1=\frac{u^2sin\left (42^{\circ} \right )}{2g}=\frac{0.669u^2}{2g}                              

At 48^{\circ},

H_{max}=H_2=\frac{u^2sin 2\left (48^{\circ} \right )}{2g}=\frac{0.743u^2}{2g}                        

 Higher maximum height value. Therefore, H1 < H2.

Posted by

shivangi.shekhar

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE