Question

What is the smallest distance ,in meters needed for an airplane touching the runway with a velocity of 360 Kmph and an acceleration of -10 meters per second square to come to rest

Answer 1

GiveN :

• Initial Velocity (u) = 360 km/h = 100 m/s
• Final velocity (v) = 0 m/s
• Acceleration (a) = -10 m/s²

To FinD :

• Distance in m need to touch the run way

SolutioN :

Use 3rd equation of motion :

$\dashrightarrow \boxed{\sf{v^2 \: - \: u^2 \: = \: 2as}} \\ \\ \dashrightarrow \tt{0 \: - \: 100^2 \: = \: 2 \: \times \: -10 \: \times \: s} \\ \\ \dashrightarrow \tt{-10000 \: = \: -20s} \\ \\ \dashrightarrow \tt{s \: = \: \dfrac{10000}{20}} \\ \\ \dashrightarrow \tt{s \: = \: 500} \\ \\ \underline{\sf{\therefore \: Distance \: travelled \: is \: 500 \: m}}$