Question

A car slows down from 27.7 m/s to 10.9 m/s in 2.37 s. What is its acceleration?

Answer 1

Answer:

$\boxed {\boxed {\sf -7.09 \ m/s^2}}$

Explanation:

We are asked to find the acceleration of a car. Acceleration is the change in velocity with respect to time. We will use the following formula:

$a= \frac {v_f-v_i}{t}$

In this formula, $v_f$ is the final velocity, $v_i$ is the initial velocity, and $t$ is the time. The car slows down from 27.7 meters per second to 10.9 meters per second in 2.37 seconds. Therefore:

• $v_f$= 10.9 m/s
• $v_i$= 27.7 m/s
• $t$= 2.37 s

Substitute the values into the formula.

$a= \frac{ 10.9 m/s-27.7 m/s}{2.37 \ s}$

Solve the numerator.

• 10.9 m/s - 27.7 m/s= -16.8 m/s

$a= \frac{-16.8 \ m/s}{2.37 \ s}$

Divide.

$a= -7.088607595 \ m/s/s$

$a= -7.088607595 \ m/s^2$

The original measurements of velocity and time have 3 significant figures, so our answer must have the same. For the number we found, that is the hundredth place. The 8 in the thousandth place tells us to round the 8 in the hundredth place up to a 9.

$a \approx - 7.09 \ m/s^2$

The acceleration of the car is approximately -7.09 meters per second squared. The acceleration is negative because the car is slowing down.

Answer 2

Answer:

- 7.088 m/s²

Explanation:

As we know that,

★ Acceleration = Change in velocity/Time

→ a = (v - u)/t

Here,

• Initial velocity (u) = 27.7 m/s
• Final velocity (v) = 10.9 m/s

→ a = (10.9 m/s - 27.7 m/s)/2.37 s

→ a = -16.8/2.37 m/s²

→ a = -7.088 m/s² [Answer]

Negative sign denotes that the velocity is decreasing.