Wednesday, 11 September 2013

I M POSTING TWO REVISION SETS FRO MY STUDENTS OF STD 9th

PHYSICS TEST
 CLASS – IX                                              CHAPTERMOTION
FULL MARKS - 30                                      - BY ABHISHEK SIR                                                                                   
       I.            Answer the following :-                                                                      5 X 1 = 5
a)      What is retardation?
b)     In which condition a body will have a certain average speed but its velocity is zero?
c)      In the given equation, what is the unit of ‘u’ and ‘a’?
s = ut + ½at²
d)     Can we say a uniform circular motion as an accelerated motion? Why?
e)     What can you say about the motion of an object whose distance – time graph is a straight line parallel to the time axis?

     II.            Solve the following :-
                                i.            A ball is gently dropped from a height of 20m. If its velocity increases uniformly at the rate of 10m/s², with what velocity will it strike the ground? After what tine will it strike the ground?                                             
                              ii.            Rahul while going to cinema hall computes the average speed for his trip to be 20km/h. While he was returning, the average speed was 30km/h. What is the average speed for Rahul’s entire travel?                                       2
                          iii.            The tip of second’s hand of a clock takes 60 seconds to move once on the circular dial of the clock. If the radius of the dial of the clock be 10.5cm, calculate the speed of the tip of the second’s hand of the clock.                  2 (π = 22/7)
                            iv.            A stone is thrown in a vertically upward direction with a velocity of 5m/s. If the acceleration of the stone during its motion is 10m/s² in the downward direction, what will be the height attained by the stone and how much time will it take to reach there?                                                                           3
                              v.            A train starts its journey from station P; accelerates at the rate of 2m/s², and reaches its maximum speed in 10s. It maintains its speed for 30min and retards uniformly to rest at the station Q after the next 20s.
Calculate:                                                                                                                  3
1.     The maximum speed of the train.
2.     Retardation
3.     The distance between stations P and Q.
                            vi.            The graph given alongside shows how the speed of a car changes with time:










                                                                                                                  3                                                                                                                                                                                                                                                                        
1.     What is the maximum speed of the car?
2.     Which part of the graph shows zero acceleration?
3.     Find the distance travelled in first 8hrs.
                        vii.            The maximum speed of a train is 80km/h. It travels 10hrs to cover a distance of 400km. Find the ratio of its maximum speed to its average speed.                                                                                                    2.5
                      viii.            A bicycle moves with a constant velocity of 5km/h for 10mins, and then decelerates at the rate of 1km/h² till it stops. Find the total distance covered by the bicycle.                                                                                       2.5
                           ix.            Graphically derive the given equations:                                                              5
1.     s = ut + ½at²
2.     v² = u² + 2as



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