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UNIFORM ACCELERATION We will consider the motion of an object such as a toy rocket that only
moves in a vertical direction with a constant
acceleration. The equations describing the motion are You are to answer each of the following questions using paper and pen
and then View
and run the uniform acceleration simulation In the simulation, you can change the values of the initial velocity u in
increments of 5 m.s-1 from -20 m.s-1 to 35 m.s-1
or change the acceleration a from -10 m.s-2
to 8 m.s-2 in increments of 2 m.s-2 by hitting the increment buttons. By changing the values of u and a in the
simulation, you can check your answers to the following questions. For any
questions that you got incorrect, you should be able to account for the
discrepancies by running the simulation with different input parameters and
hence gain a better understanding of the physics. This technique of POE (Predict Observe
Explain) is a powerful learning strategy that will
help you improve your study methods. Questions Verical Motion: up
is taken as the positive direction. Initial
conditions t = 0, s
= 0 1.
What is the
shape of the displacement s /
time t graph for a < 0 and a > 0? 2.
What is the
shape of the velocity v / time t
graph for a < 0 and a > 0? 3.
What is the
shape of the acceleration a / time t graph for a < 0 and a > 0? 4.
If a < 0 and u > 0, what is the velocity v of the object
when it reaches its maximum height? What is the acceleration a when the object stops at its highest point? What is the slope
of the a / t when the object is at its highest point? What is the slope of
the v / t when the object is at its highest point? Compare the times for the object to reach
its maximum height and then return to s = 0. 5.
What is the
acceleration a of the object
when it is moving up or moving down? 6.
What is the
slope of the s / t when the object is moving up? 7.
What is the
slope of the s / t when the object is moving down? 8.
What is the
slope of the s / t when the object is at its highest point? 9.
What
quantity does the slope of the s / t graph correspond too? 10.
What is the
slope of the v / t when the object is moving up? 11.
What is the
slope of the v / t when the object is moving down? 12.
What
quantity does the slope of the v / t
graph correspond too? 13.
What is the
slope of the a / t
when the object is moving up? 14.
What is the
slope of the a / t when the object is moving down? 15.
Sketch the three
graphs for the motion of a ball thrown vertically into the air (up is
positive) when u = 20 m.s-1 and a = -10 m.s-2.
s / t v / t a / t 16.
What are the
changes in the three graphs when only the initial velocity is changed? 17.
What are
the changes in the three graphs when only the acceleration is changed? 18.
At time t = 0 s and s = 0 m, the initial velocity is u =
20 m.s-1and a = -10 m.s‑2. Calculate the following for the
motion of the object: (a) The velocity when the displacement is again zero, s = 0 m. (b) The time
taken to return to s = 0 m. (c) The maximum
height. (d) The velocity at the
maximum height. (e) The time taken to
reach the maximum height. (f) When time t = 1.0 s,
calculate the acceleration, the velocity and displacement of the object. (g) When time t = 3.0 s,
calculate the acceleration, the velocity and displacement of the object. 19.
Given t = 0, s = 0, a = 4.0 m.s-2 and u = -20 m.s-1.
Sketch the three graphs
s / t v / t a / t Calculate
the following for the motion of the object at time t = 5.0 s and t = 10 s:
(a) acceleration, (b) velocity, and (c) displacement. Ian Cooper Any comments, corrections, suggestion email: matlabvisualphysics@gmail.com |
