Question

A car accelerates uniformly from rest to a speed of 20 m/s in 10 seconds. What is the car's acceleration?

• A. \( 1.0 \, \text{m/s}^2 \)
• B. \( 2.0 \, \text{m/s}^2 \)
• C. \( 0.5 \, \text{m/s}^2 \)
• D. \( 4.0 \, \text{m/s}^2 \)

Hint:

Acceleration can be calculated from the change in velocity over time. If the object is at rest initially, the formula simplifies to \( a = \frac{v}{t} \).

Answer 1

The Correct Option is A

The car starts from rest, so the initial velocity \( u = 0 \, \text{m/s} \), and it reaches a final velocity \( v = 20 \, \text{m/s} \) in \( t = 10 \, \text{s} \). Using the equation for acceleration: \[ a = \frac{v - u}{t} \] Substitute the given values: \[ a = \frac{20 - 0}{10} = \frac{20}{10} = 2.0 \, \text{m/s}^2 \] Thus, the car's acceleration is \( 2.0 \, \text{m/s}^2 \).