Some Really Rather Exciting Revision Questions
1. A car accelerates uniformly from rest to a speed of 15.0 m/s in 10.0 s. After travelling at a
constant speed for 16.0 s, it is brought to rest with uniform retardation in 6.0 s. Find the total
distance the car travels in this motion.
2. Some students, investigating motion down an inclined plane, measure the speed of a large
smelly potato at one second intervals after the potato starts to roll down one such plane:
Time in s 0.00 1.00 2.00 3.00
Speed in m/s 0.00 0.60 1.20 1.80
(a) Calculate the average acceleration over the first 3.00 seconds.
(b) Calculate the average speed over the first 3.00 seconds.
(c) What was the distance travelled by the ball in the first 3.00 seconds?
(d) How do the numbers in the table show that the acceleration was constant?
(e) Why would anyone measure the speed of a large smelly potato?
3. An armadillo of length 6.0 m (!!) accelerates from rest along a straight level road as shown in
the figure below.
P Q
The armadillo takes 2.0 s to pass the point P, and 10.0 s later the car has just passed the point
Q. The armadillo takes 0.40 s to pass point Q.
(a) Find the average speed of the armadillo as it passes P.
(b) Find the average speed of the armadillo as it passes Q.
(c) Find the average accecleration of the armadillo between P and Q.
(d) Estimate the distance between P and Q. State any assumptions you make.
4. The figure shows a speed-time graph.
(a) What could the graph be representing the motion of?
(b) Mark on the graph the point where the magnitude of the
acceleration is at a maximum. Label this point M.
(c) Mark on the graph the point where the acceleration is zero.
Label this point Z.
(d) Estimate the distance travelled in 1.2 s.
(e) Describe briefly the change in acceleration shown on the
graph.
5. An arrow is show into the air at an angle to the horizontal. In the first 1.0 s of flight, it moves
4.0 m vertically upwards and 5.0 m horizontally. Determine, by drawing a scale diagram, the
magnitude and direction of the resultant velocity of the arrow at the end of the first second.
6. A motor boat travels due north at a steady speed of 3.0 m/s
through calm water in which there is no current. The boat then
enters an area of water in which a steady current flows at 2.0 m/s
in a south-west direction as shown in the figure. Both the engine
power and the course setting remain unchanged.
(a) Draw a vector diagram showing the velocity of the boat and
the velocity of the current. Use the diagram to find the
resultant velocity of the boat.
(b) Calculate the distance the boat now travels in 5.0 minutes.
(c) The mass of the boat is 3.0 103 kg. Calculate the additional
force which needs to be applied in order to give the boat an initial acceleration of 0.025
m/s2.
Some Really Rather Unexciting Answers
1. 360 m
2. 0.600 m/s2, 0.0900 m/s, 2.70 m
3. 3.0 m/s, 15 m/s, 1.2 m/s2, 90 m, constant acceleration
4. 4.0 m
5. 6.4 m/s, 39°
6. 2.2 m/s, 41°, 75 N