Question

A motorcycle starts from rest and accelerates uniformly to a speed of 54 kmph over a distance of 450 m. Then the acceleration of the motorcycle is
1. 1.33 m/s2
2. 0.40 m/s2
3. 0.25 m/s²
4. 2 m/s2

Answer 1

Correct Answer - Option 3 : 0.25 m/s²

The correct answer is option 3) i.e. 0.25 m/s2

CONCEPT:

Kinematic equations of motion:

These equations define the relationship between initial velocity u, final velocity v, time t, and displacement s of an object with respect to its motion in uniform acceleration a.

Following are the three kinematic equations for uniformly accelerated motion:

• v = u + at
• s = ut + 0.5at2
• v2 - u2 = 2as

CALCULATION:

Since the motorcycle moves from rest, initial velocity u = 0 m/s

Final velocity, v = 54 kmph = 54 × (5/18) = 15 m/s

Displacement, s = 450 m

⇒ v2 - u2 = 2as

⇒ 152 - 02 = 2 × a × 450

⇒ a = 0.25 m/s²