Question

a car accelerate uniform by from 20km/h to 40km/h in 5 sec. calculate (i)the acceleration
(i ) the distance covered by car in that time.

Answer 1

Hello 
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Here 
u = 20 km / h  = 5.5  m/s
v = 40 km / h  = 11.1 m/s
t  = 5 seconds 
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v = u + at 
a = v-u/t
a = 11.1-5.5/5
   = 5.6/5
   = 1.12 m/s²
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v² - u² = 2as 
(11.1)² - (5.5)²  = 2 x 1.12 x s 
123.21 - 30.25 = 2.24 x s 
92.96               = 2.24 x s 
s = 92.96/2.24
s = 41.5 m 
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