Question

the velocity of a body moving at an initial velocity of 20 m s-1 and having an acceleration of 4 m s -2 after 2s will be
(a)24 m s-1
(b)28 m s-1
(c)32 m s-1
(d)40 m s-1

Answer 1

Hey Mate !

Here is your solution :

Given,

Initial velocity ( u ) = 20 ms^( -1 ) = 20 m/s

Time ( t ) = 2 s

Acceleration ( a ) = 4 ms^( -2 ) = 4 m/s^2

Final velocity ( v ) = ?

Using 1st equation of Motion ,

=> v = u + at

=> v = ( 20 m/s ) + ( 4 m/s^2 ) × ( 2 s )

=> v = ( 20 m/s ) +( 8 m/s )

=> v = 28 m/s = 28 ms^( -1 )

Hence, answer is option ( b ) 28 ms^( -1 ).

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Hope it helps !! ^_^