Question

he given velocity-time graph depicts the motion of an object moving in a straight line. If total distance covered by object is 120 m, then the time duration for which the object has undergone retardation is

Answer 1

Because area bounded by (v-t) graph is displacement of the body –
     
Let total time = t              

Area = (15 x 4) + ½ (t-4) (15)    
           
60+15/2 (t-4) = 120  
            
15/2 (t-4) = 120 – 60     
          
(t – 4) = 60/15 X 2    
             
(t-4)   = 8       
        
T = 12 seconds  

Time for retardation = 12 – 4 seconds = 8 seconds