Two cars A and B are moving in same direction with velocities 30 m / s and 20 m / s. When car A is at a distance d behind the car B, the driver of the car A applies brakes producing uniform retardation of 2 m / s 2. There will be no collision when

Question

Two cars A and B are moving in same direction with velocities 30 m / s and 20 m / s. When car A is at a distance d behind the car B, the driver of the car A applies brakes producing uniform retardation of 2 m / s 2. There will be no collision when (A) d < 2.5 m (B) d > 125 m (C) d >25 m (D) d < 125 m

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/0c2e9ff6036a6c91cef1ed00eefeafc6-.png" /> v2=u2+2 a d ⇒ 0=(10)2-2 × 2 × d rel ⇒ (100/4) ≤ d rel ⇒ d rel ≥ 25 m

Q. Two cars $A$ and $B$ are moving in same direction with velocities $30 m / s$ and $20 m / s$ . When car $A$ is at a distance $d$ behind the car $B$ , the driver of the car $A$ applies brakes producing uniform retardation of $2 m / s^{2}$ . There will be no collision when

d < 2.5 m

d > 125 m

d >25 m

d < 125 m

$v^{2} = u^{2} + 2 a d$
$\Rightarrow 0 = (10)^{2} - 2 \times 2 \times d_{re l}$
$\Rightarrow \frac{100}{4} \leq d_{re l}$
$\Rightarrow d_{re l} \geq 25 m$

Q. Two cars A and B are moving in same direction with velocities 30m/s and 20m/s. When car A is at a distance d behind the car B, the driver of the car A applies brakes producing uniform retardation of 2m/s2. There will be no collision when