Question

The equation of motion of a projectile is, y = 12x – $\frac{3}{4}$x²

The horizontal component of velocity is 3 m s^–1. Given that g = 10 m s^–2, what is range of the projectile?

• A. 12.4 m
• B. 21.6 m
• C. 30.6 m
• D. 36.0 m

Answer 1

Answer: (B)

21.6 m

Answer 2

y = 12x – $\frac { 3 } { 4 }$ x²

\12 = $\frac { u _ { y } } { u _ { x } }$ ̃ u_y = 12 u_x = 12 (3) = 36

Range = $\frac { 2 u _ { x } u _ { y } } { g }$ = $\frac { 2 ( 3 ) ( 36 ) } { 10 }$ = 21.6 m