Please answer this Question.30

Please answer this Question.30 30. A car starts from rest and accelerates uniformly at Ian's: for I conds It then Constant for next 20 seconds. The brakes are applied and Car uniforrnly retarded and it comes to test in 5 seconds. Draw a velocity-time graph and it to find (a) maximum velocity reached, (c) •acceleration between 10 to 30 secon&. (e) average velocity of the car (b) retardation in last 5 (d) unal distance travelled, -20 m 31. A car travels with a uniform velocity m s-l for 5 S. brakes are applied and car comes to rest with a uniform retardation in a further 10 s. Draw grt ami use it to tind

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a) A c c e l e r a t i o n i s g i v e n b y s l o p e o f v - t g r a p h a = \frac{m a x i m u m v e l o c i t y}{t i m e} m a x i m u m v e l o c i t y = 10 \times 10 = 100 m / s e b) r e t a r d a t i o n = \frac{100}{5} = 20 m / s e c s q u a r e c) a c c e l e r a t i o n b e t w e e n 10 t o 30 s e c i s z e r o a s s l o p e o f g r a p h i s z e r o a n d t h e b o d y i s m o v i n g w i t h c o n s \tan t v e l o c i t y . d) t o t a l d i s \tan c e i s t h e a r e a u n d e r g r a p h = \frac{1}{2} \times 100 \times 10 + 100 \times 20 + \frac{1}{2} \times 5 \times 100 = 2750 m e) a v e r a g e v e l o c i t y = T o t a l d i s p l a c e m e n t / t o t a l t i m e = 2750 / 35 = 78.57 m / s e c R E G A R D S