Exercise : Motion, Heat

Exercise 1

1   A car travels along a straight road. The speedometer readings after every 5 s is tabulated below.
        Time (s)                                      Speed (m/s)     
            0                                                        0
            5                                                        10
            10                                                      20
            15                                                      30
            20                                                     30
            25                                                     30
            30                                                     30
            35                                                     15
            40                                                     0


(a) Draw a speed - time graph to show the variation os speed with time.
(b) Describe the motion of the car
(c) How far from the starting point is the car after 20 s ?
(d) What is the total distance travelled by the car ?
(e) What is the average speed of the car ?


Exercise 2

1. A student has been asked to determine, as accurately as possible, the external diameter and length of a plastic  tube. The  plastic tube is about 0.6 cm diameter and 10 cm in long.
Which pair of measuring instruments should the student use ?
          Length                         Diameter
(A)    micrometer                 metre rule
(B)   vernier calipers           micrometer
(C)   vernier calipers           vernier
(D)   micrometer                  calipers
                                                                                 (B)

2. The diagram below shows part of a vernier scale.

 
What is the correct reading ?
(A)   30.5 mm                    (B)   32.5 mm
(C)   37.0 mm                    (D)   43.0 mm
                                                                         (B)
3.  A tunnel has a length of 2.5 km. A car takes 4 min to travel between the two ends of the tunnel. What is the average speed of the car ?
(A) 10.42 m/s                    (B)    0.69 m/s
(C)  42.67 m/s                    (D)   625 m/s              (A)


4.   A car takes 1 hour to travel 50 km along a highway and then 0.3 hour to travel 15 km along a side road. What is the average speed of the car for the whole journey ?
(A)   45 km/ h                    (B)   50 km/h
(C)   55 km/h                     (D)   60 km/h             (B)

5.   Which quantity X is calculated using this equation ?

(A)   Instantaneous velocity          (B)   Average speed
(C)   Average velocity                     (D)   Acceleration                    (B)



6.   A stone falls freely from the top of a cliff into the sea. Air resistance may be ignored. Which statement describes its motion ?
(A)   It falls with decreasing speed                 (B)   It falls with decreasing acceleration
(C)   It falls with constant speed                     (D)   It falls with constant acceleration
                                                                                                                                                           (D)


7.   A car accelerates from traffic lights. The graph shows how the car's speed changes with time.

How far does the car travel before it reaches a steady speed ?
(A)   10 m                       (B)   20 m
(C)   100 m                     (D)  200 m                             (C)

8.   An aeroplane is launched vertically upwards into the air and its velocity - time graph is shown below.   

What is the maximum displacement made by the aeroplane ?
(A)   30 m                         (B)   60 m
(C)   120 m                       (D)   240 m                            (C)

9.   A trolley runs down a slope from rest. In the first 3 seconds it travels 3.2 m. What is the constant acceleration ?
                     (C)

10.   A girl throws a stone vertically up to a woman standing at a height of 2.0 m above the woman. If the stone is thrown up with a velocity of 7.0 m/s, what is the velocity of the stone at the instant when it is caught by the woman ?
(A)   3.0 m/s                    (B)   6.2 m/s
(C)   9.0 m/s                    (D)   9.4 m/s                           (A)

11.   Which states of matter are very difficult to compress and has a fixed volume ?
(A)   Solid, liquid and gas
(B)   Solid and liquid only
(C)   Liquid only
(D)   Solid only                                    (B)
12. The graph shows the change in temperature of a material as it is heated.  Which part on the graph shows when the material is boiling ?
 
(A)   A         (B)   B          (C)   C        (D)   D                                         (D)

13.   The graph shows the speed of a car as it accelerates from rest. What can be said about the acceleration of the car ?


(A)   increases throughout the journey
(B)   decreases throughout the journey
(C)   increases, becomes constant and then decreases
(D)   decreases, becomes constant and then increases                      (C)


14.  The graph shows how the speed of an object varies with time.

Which of the following is correct ?
(A)   The average speed of the object during the first 4 s is 20 m/s
(B)   The acceleration of the object during the first second is 20 m/s2
(C)   The deceleration of the object is 10 m/s2
(D)   The object is traveling at a constant speed during the last second             (B)