Related Formula
H = (u² ²θ)/(2g) and T = (2u θ)/(g)$$H = \frac{u^2 \sin^2\theta}{2g} \quad \text{and} \quad T = \frac{2u \sin\theta}{g}$$
where,
H$H$ = maximum height reached
T$T$ = total time of flight
u$u$ = initial projection velocity
θ$\theta$ = angle of projection
Core Logic
From the formulas, we see that:
H ∝ ²θ and T ∝ θ$$H \propto \sin^2\theta \quad \text{and} \quad T \propto \sin\theta$$
Thus, we can directly link time of flight to the square root of the maximum height:
T ∝ √(H) (T₁)/(T₂) = √((H₁)/(H₂))$$T \propto \sqrt{H} \implies \frac{T_1}{T_2} = \sqrt{\frac{H_1}{H_2}}$$
Step 1: Compute Ratio
Given:
H₁ = 8 H₂ (H₁)/(H₂) = 8$$H_1 = 8 H_2 \implies \frac{H_1}{H_2} = 8$$
Substitute this ratio:
(T₁)/(T₂) = √(8) = 2√(2)$$\frac{T_1}{T_2} = \sqrt{8} = 2\sqrt{2}$$
Thus, the ratio is 2√(2) : 1$2\sqrt{2} : 1$.
Pattern Recognition
Sees: Projectile heights ratio → Time of flight ratio.
Shortcut: Since H ∝ uy²$H \propto u_y^2$ and T ∝ uy$T \propto u_y$, we have T ∝ √(H)$T \propto \sqrt{H}$. If the height is 8 times larger, the flying time is √(8) = 2√(2)$\sqrt{8} = 2\sqrt{2}$ times larger. ✓
Chapter Mix
Class 11 Physics: Kinematics