Question

A plane starts from rest with acceleration of $3\,ms^{-2}$ and makes a run for $35\, s$ before taking off. The minimum length of runway and velocity of plane at take off are respectively

• A. $1838\, m, 105 \,ms^{-1}$
• B. $1388\, m, 501\, ms^{-1}$
• C. $3188\, m, 51\, m s^{-1}$
• D. $838\, m, 95 \,ms^{-1}.$

Answer 1

Answer: (A)

Using S = $ut + \frac{1}{2} at^2$, we get
S = $0 + \frac{1}{2} \times 3 \times 35^2$ = 1837.5 m
Using $\upsilon = u + at$ , we get $\upsilon = 0 + 3 \times 35 = 105 \, m \, s^{-1}$