Question

The frontal area of a small motorcycle is 0.60 m2, its drag coefficient is 0.62, and its maximum speed is 150 kph. next, the driver lowers his head and effectively reduces the frontal area to 0.58 m2, and the drag coefficient to 0.60. assuming the power of the engine is unchanged, estimate the new maximum speed (rho = 1.2 kg/m3).

Answer 1

The estimated new maximum speed is approximately 157 kph. To estimate the new maximum speed of the motorcycle, we can use the equation for drag force.

Step-by-step explanation:

To estimate the new maximum speed of the motorcycle, we can use the equation:

Drag force = 0.5 * rho * Cd * A * V²

Where:

Drag force is the force opposing motion caused by air resistance

rho is the density of air (given as 1.2 kg/m³)

Cd is the drag coefficient

A is the frontal area

V is the velocity

We are given the initial values for Cd, A, and V. We can rearrange the formula to solve for the new velocity:

1/2 ⋅ ρ ⋅ A₁ ⋅ Cd1 ⋅ v₁³ = 1/2⋅ ρ ⋅ A₂ ⋅ Cd2 ⋅ v₂³

Now, solving for v₂ (new speed):

v₂ = (v₁ ⋅A₁ ⋅ Cd1)/(A₂ ⋅ Cd2)^(1/3)

Substituting the given values:

v₂ = 150 kph * [(0.60 m² * 0.62) / (0.58 m² * 0.60)]^(1/3) = 157 kph.