Cheetahs are adapted for speed as the fastest land animals, reaching faster artes than most sport cars. They have ben measured to accelerate at rates of 10 m/s^2+. A sport car can accelerate at about 7. m/s^2 and cheetahs can go from rest to 10 m/s in only three strides.
Like finding an object's displacement or change in position by finding the area under a velocity-time graph, an object's velocity changes from the area under an acceleration-time graph, which has the acceleration on the vertical and horizontal axis.
Figure 2 shows a cheetah's motion with points lying along a horizontal straight line with a non-zero y-intercept. The acceleration is a constant 4.0 m/s^2, so this graph represents uniform acceleration.
Figure 2 Acceleration-time graph showing motion with uniform acceleration
By calculating the green area, we can determine the object's velocity change from t = 0 s to t = 50 s:
t = 5
m/s^2 = 4
A = tw
A = 5s x 4 m/s^2 [W]
A = 20 m/s^2 [W]
→
v = 20 m/s^2 [W] - The green area is the object's change in velocity.
If the cheetah's initial velocity is 0 (it's at rest), the final velocity is equal ot the change in velcoity, 20m/s [W]. If the initial velocity is 5 m/s [W], but then the graph shows tha thte final velocity is
5 m/s [W] =20 m/s [W] = 25 m/s [W]
The graph doesn't shows what the initial and final velocities are; just the velocity change occuring in the time interval.
Graphical analysis is among the best analytical tools for physicists. In objects' motions, analyzing position-time, velocity-time, and acceleration-time graph can show real-life events like the cheetah's motion, which is crucial as most object in nature don't have a speedometer.
The 3 graphs compare 3 types of linear motion graphs, which show the same type of motion: uniform, acceleration, but look differents.
1st: Position-time graph, 2nd: velocity-time, and 3rd: acceleration-time graphs of the same motion
First, calculate the green area like earlier like a:
→
t(s) x m/s [W] = v
3. Plot the data to create a velocity-time graph.
This graph and previous one both describe uniform acceleration.
2. Show the calculation of the area under the graph at 1 s intervals from t = 0 s to t = 5.0 s.