A car starting from rest is accelerated uniformly to a velocity at 100.8km/h. it brake is applied in 4 seconds, find its acceleration and its retardation converting from km/h to ms.
I think it is asking what is the acceleration when slowing after is starts at the initial velocity of 100.8km/h (change that to m/s). How long is the brake applied?
Well, well, well! Looks like this car is really speeding things up, then hitting the brakes just as fast. Let's calculate the acceleration and retardation, shall we?
First, we need to convert the final velocity from km/h to m/s, because we want everything in the same units to avoid confusion. To do that, we divide 100.8 km/h by 3.6 (since there are 3,600 seconds in an hour and 1 kilometer is 1,000 meters).
So, 100.8 km/h ÷ 3.6 = 28 m/s (approximately).
Now, let's find the acceleration. Since the car starts from rest and reaches a certain velocity in a given time, we can use the formula: acceleration (a) = (change in velocity)/time.
In this case, the change in velocity is 28 m/s (final velocity) - 0 m/s (initial velocity) = 28 m/s.
The time taken to reach 28 m/s is not provided, but don't worry! We can assume it to be the same as the time it takes to apply the brakes, which is given as 4 seconds.
So, acceleration (a) = (change in velocity)/time = 28 m/s / 4 s = 7 m/s².
Now, let's find the retardation (deceleration) when the brakes are applied. Retardation is just the negative value of acceleration.
Therefore, retardation = -7 m/s² (you could also say -7 m/s² is the value of "pulling the brake" or "letting go of the accelerator pedal" really fast).
And there you have it! The acceleration is 7 m/s², and the retardation (or deceleration) is -7 m/s². This car is definitely giving us a roller coaster ride of emotions!
Pls can u help me out with my question
a velocity
A car starting from rest accelerated uniformly to vel, of 100.8km/h convert it to m/s
To find the acceleration of the car, we can use the following equation:
a = (vf - vi) / t
where:
a = acceleration
vf = final velocity
vi = initial velocity
t = time taken
Given that the car starts from rest, the initial velocity (vi) is 0 km/h. The final velocity (vf) is 100.8 km/h. The time taken (t) is 4 seconds.
To convert the velocities from km/h to m/s, we need to use the conversion factor:
1 km/h = 1000 m/3600 s = 5/18 m/s
Now let's apply the conversion and calculate the acceleration:
vi = 0 km/h = 0 m/s
vf = 100.8 km/h = (100.8 * 5/18) m/s ≈ 28.0 m/s
t = 4 s
a = (28.0 - 0) m/s / 4 s
a ≈ 7.0 m/s²
Therefore, the acceleration of the car is approximately 7.0 m/s².
To find the retardation (deceleration) of the car, we can use the same formula but with reverse sign:
retardation = (vf - vi) / t
Since the car is braking, the final velocity (vf) is 0 m/s, and the initial velocity (vi) is 100.8 km/h. We can convert vi to m/s using the same conversion factor:
vi = 100.8 km/h = (100.8 * 5/18) m/s ≈ 28.0 m/s
vf = 0 m/s
t = 4 s
retardation = (0 - 28.0) m/s / 4 s
retardation ≈ -7.0 m/s²
Therefore, the retardation (deceleration) of the car is approximately -7.0 m/s². Note that the negative sign indicates the opposite direction of motion, indicating deceleration or braking.