A cyclist cycles for t second at a speed of 3 m/s and then for the same time at a speed of 5 m/s along a straight road to north. What is the average speed of the cyclist?
Given:
v₁ = 3 m/s ; d₁ = ? ; t₁ = ?
v₂ = 5 m/s ; d₂ = ? ; t₂ = ?
But, there is another data that t₁ = t₂
v₂ = 5 m/s ; d₂ = ? ; t₂ = ?
But, there is another data that t₁ = t₂
So let us take as,
t₁ = t₂ = t
t₁ = t₂ = t
To find:
Average speed
Solution:
d₁ = v₁ × t₁
= 3 ms⁻¹ × t s
= (3t) m
d₂ = v₂ × t₂
= 5 ms⁻¹ × t s
= (5t) m
Average speed = (d₁ + d₂) /(t₁ + t₂)
= (3t m + 5t m) / (t s + t s)
= (8t m) / (2t s)
= 4 m/s
∴ Average speed = 4 m/s
