Explanation :
It is given that, the driver accelerates from a stop sign, cruises for 20 s at a constant speed of 60 km/h, and then brakes to come to a stop 40 s after leaving the stop sign.
We know that acceleration is defined as the rate of change of velocity.
Where
dv is the change in velocity, dv = 0 - 60 m/s = -60 m/s
dt is the change in time, dt = 40 s - 30 s = 10 s
So, 
From the graph it is clear that, from 30 s to 40 s the car is decelerating. So, at every second within this time the value of acceleration will be same i.e. 
.
I believe the answer is manipulation of information. Hope I helped!
The rate at which velocity changes is called acceleration. (Attensity exists when velocity varies.) If a moving object changes speed.
Why does time accelerate the rate at which velocity changes?
A motion's acceleration is the rate at which it changes from one velocity to another. A velocity's rate of change with respect to time is referred to as its acceleration. The amount and direction of acceleration are both properties of a vector quantity.
A change in velocity is known as what?
A velocity change's acceleration is measured. Acceleration is the measure of how quickly a velocity changes with time. The acceleration measure used in SI is M/s2.
To know more about velocity visit: brainly.com/question/18084516?
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Answer:
0.76
Explanation:
we are given:
radius (r) =5.7 m
speed (s) = 1 revolution in 5.5 seconds
acceleration due to gravity (g) = 9.8 m/s^{2}
coefficient of friction (Uk) = ?
we can get the minimum coefficient of friction from the equation below
centrifugal force = frictional force
m x r x ω^{2} = Uk x m x g
r x ω^{2} = Uk x g
Uk = 
where ω (angular velocity) = 
= 
= 1.14
Uk = 
= 0.76
Given parameters:
Mass of the car = 1000kg
Unknown:
Height = ?
To find the heights for the different amount potential energy given, we need to understand what potential energy is.
Potential energy is the energy at rest due to the position of a body.
It is mathematically expressed as:
P.E = mgh
m is the mass
g is the acceleration due to gravity = 9.8m/s²
h is the height of the car
Now the unknown is h, height and we make it the subject of the expression to make for easy calculation.
h = 
<u>For 2.0 x 10³ J;</u>
h = 
= 0.204m
<u>For 2.0 x 10⁵ J;</u>
h = 
= 20.4m
<u>For 1.0kJ = 1 x 10³J; </u>
h = 
= 0.102m
