A racing car reaches a speed of 40 m/s. At this instant, it begins a uniform negative acceleration, using a parachute and a braking system, and comes to rest 5.0 s.
(a)Determine the acceleration of the car.
Work:
40m/s x 5s = 200m
(0)^2=(40)^2 +2a(200)
a=-4 m/s^2
(b) How far does the car travel after acceleration starts?
200 m?
No. The distance it traveled was 100m. Averagevelocity during stopping was 1/2 40 * 5
is part (a) right, then? a= -4m/s^2
a racing car reaches a speed of 44m/s. at this instandt, it behins a uniform deceleration using a parachute and a braking system, and comes to a rest 4.8s later. Find the acceleration of the car
To determine how far the car travels after the acceleration starts, we need to calculate the distance covered during the period of negative acceleration.
Given that the car comes to rest in 5.0 seconds, we can use the equation of motion:
vf^2 = vi^2 + 2ad
where:
vf = final velocity (0 m/s, as the car comes to rest)
vi = initial velocity (40 m/s)
a = acceleration
d = distance traveled
Plugging in the known values, we have:
(0)^2 = (40)^2 + 2a(d)
Simplifying the equation, we get:
0 = 1600 + 2ad
Since we know that the car travels 200 meters before the acceleration starts, we can subtract that distance from the total distance:
0 = 1600 + 2a(d - 200)
Solving for the remaining distance, we get:
2a(d - 200) = -1600
d - 200 = -800/a
d = -800/a + 200
Now, using the acceleration value we found earlier (a = -4 m/s^2), we can substitute it into the equation:
d = -800/(-4) + 200
d = 200 + 200
d = 400
Therefore, the car travels an additional 400 meters after the acceleration starts.
Part a should be:
40m/s / 5.0s = 8.0m/s^2