Question

A sports car has an average acceleration of 5.81 m/s2. How long does it take for the car to reach 60.0 mi/h, if it starts from rest?

Answer 1

4.62 s

Step-by-step explanation:

We have 3 known variables and 1 unknown variable that we want to solve for.

• a = 5.81 m/s²
• v₀ = 0 m/s
• v = 60.0 mi/h
• t = ?

Convert 60 mi/h to m/s.

• 60 mi/h -> 26.8224 m/s

Use the kinematic equation that contains all four of these variables.

• v = v₀ + at

• 26.8224 = 0 + (5.81)t
• 26.8224 = 5.81t
• t = 4.61659208262

It takes the car 4.62 seconds to reach a velocity of 60 mi/h (26.82 m/s) if it starts from rest.

Answer 2

4.617 s

Step-by-step explanation:

The speed of 60 mi/h can be converted to m/s:

(60 mi/h) × (1609.344 m/mi) × (1 h)/(3600 s) = 26.8244 m/s

The relationship between speed and acceleration is ...

v = at

t = v/a = (26.8244 m/s)/(5.81 m/s²) ≈ 4.617 s

It will take the car 4.617 seconds to reach 60 mi/h starting from rest.