I will be demonstrating
Acceleration 1 - know the difference between acceleration and velocity
Acceleration 2 - I can calculate the acceleration of an object with direction and proper units
Acceleration 3 - I can interpret diagrams for objects moving with changing velocity
Acceleration 4 - I can draw velocity vs time graph for changing velocity
Acceleration 6 - I can use the motion concpets to solve problems involving objects with changing velocity
Acceleration 1 - know the difference between acceleration and velocity
Acceleration 2 - I can calculate the acceleration of an object with direction and proper units
Acceleration 3 - I can interpret diagrams for objects moving with changing velocity
Acceleration 4 - I can draw velocity vs time graph for changing velocity
Acceleration 6 - I can use the motion concpets to solve problems involving objects with changing velocity
QuestionsA plot of velocity versus time for an object in linear motion. (a) what are the instataneous velocities at t=8.0s and t=11.0s. (b) Compute the final displacement of the velocity. (c) compute the total distance the object travels.
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Answersa) To find the instanteous velocities at certain times, you look at the vt graph move along the time axis until you find the specified time, find the point directly above or below, and then see what number it equals to on the velocity =axis. In this case, the instaneous velocity at t =8.0s is -12m/s and at t=1.05s is -4m/s.
b)To find the final displacement of an object I must look at the vt graph and find the areas between the lines and time axis. Then, you add them(make sure you pay attention to the signs of the areas). In this case, using the lines on a graph (as shown by the shading above). The area of the triangle is represented by A = 1/2bh, so the area of the first triangle is A=1/2(4)(8) = 16m and the area of the second is A =1/2(4.5)(12) = -27m. The area of the trapezoid is A=1/2(15+2)(-4) = 7m. By adding these areas up we find the final displacement of the object is (16m) +(-27m) +(7m) = -18m. C) In order to find the total distance of an object travelts, you again find the areas that are encompassed by the lines and time axis. However this time you ignore whether or not these areas are positive or negative and add them as if they are all positive since we want the full distance the object moved. By using the numbers from part b, we can find the total distance the object travelts is 16m+27m+7m = 50m. |
I apologize for the crude drawing, but this is the qualative motion map, accleration graph, and position graph for the given velocity graph shown above. Acceleration can be graphed as straight lines only because they represent a constant change in velocity. When there is no acceleration, that indicates that either there is no velocity at all or velocity is constant and not increasing.