Answer:
Average speed (s) = total distance/total elapsed tiime
Explanation:
To calculate the average speed of an object, you must know the total distance an object travels and the total elapsed time of its whole journey.
 
 
        
                    
             
        
        
        
Answer:
Moment of inertia of Earth about its own axis is given as

Explanation:
Since Earth is considered as solid sphere
So we will have

so we will have

so we have

 
        
             
        
        
        
Answer:
Explanation:
Given that,
Initial speed of the girl is
u = 1.4m/s
Height she is going is 
H = 2.45m
Incline plane she will pass to that height
L = 12.4m
Mass of girl and bicycle is
M=60kg
Frictional force that oppose motion is 
Fr = 41N
Speed at lower end of inclined plane 
V2 = 6.7m/s
Work done by the girl when the car travel downward
Using conservation of energy 
K.E(top) + P.E(top) + work = K.E(bottom) + P.E(bottom) + Wfr
Where Wfr is work done by friction 
Wfr = Fr × d 
P.E(bottom) is zero, sicne the height is zero at the ground 
K.E is given as ½mv²
Then,
½M•u² + MgH + W = ½M•V2² + 0 + Fr×d
½ × 60 × 1.4² + 60×9.8 × 2.45 + W = ½ × 60 × 6.7² + 41 × 12.4
58.8 + 1440.5 + W = 1855.1
W = 1885.1 —58.8 —1440.5
W = 355.8 J
 
        
             
        
        
        
Answer:
not really 
Explanation:
you are always doing something