Question

A man sees a deer in the road and slams on his brakes. If he is traveling at 45.2 m/s and comes to a stop in 2.74 s, what is his acceleration? O -6:02 m/s2 -0.0606 m/s2 -47.9 m/s2 0 -16.5 m/s2 ​

Answer 1

16.50 m/s²

Step-by-step explanation:

initial velocity(u)=45.2 m/s

final velocity(v)= 0 (it stops)

time taken(t)= 2.74 s

now,we have

acceleration(a)= (v-u)/t

= (0-45.2 m/s)/2.74s

= -45.2 m/s / 2.74s

= -16.50 m/s²

Answer 2

`\boxed {\boxed {\sf -16.5 \ m/s^2}}`

Step-by-step explanation:

We are asked to find the acceleration of a man driving. Acceleration is the change in velocity over the change in time. Acceleration is calculated with the following formula.

`a= (v_f- v_i)/(t)`

The driver's initial velocity is 45.2 meters per second. His final velocity is 0 meters per second because he came to a stop. He stopped in 2.74 seconds.

`\bullet \ v_f= 0 \ m/s \\\bullet \ v_i= 45.2 \ m/s \\\bullet \ t= 2.74 \ s`

Substitute these values into the formula.

`a= (0 \ m/s - 45.2 \ m/s )/( 2.74 \ s)`

Solve the numerator by subtracting.

`a= (- 45.2 \ m/s )/( 2.74 \ s)`

`a= -16.49635036 \ 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 calculated, that is the tenths place. The 9 in the hundredth place tells us to round the 4 in the tenths place up to a 5.

`a \approx -16.5 \ m/s^2`

The acceleration is approximately -16.5 meters per second squared. The acceleration is negative because the man slowed down and came to a stop.