Answer:
[tex]\boxed {\boxed {\sf -6 \ m/s^2}}[/tex]
Explanation:
Acceleration is the change in velocity with respect to time. We are given the velocity and time, so we will use the following formula to find acceleration.
[tex]a= \frac {v_f-v_i}{t}[/tex]
The car slowed down, so the final velocity was 10 meters per second and the initial velocity was 40 meters per second. It slowed down in 5 seconds.
Substitute these values into the formula.
[tex]a= \frac{ 10 \ m/s - 40 \ m/s}{5 \ s}[/tex]
Solve the numerator and subtract.
[tex]a= \frac{ -30 \ m/s}{5 \ s}[/tex]
Divide.
[tex]a= -6 \ m/s/s[/tex]
[tex]a= -6 m/s^2[/tex]
The acceleration of the car is -6 m/s² or -6 meters per second squared. The acceleration is negative because the car slowed down.