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a driver traveling 20m/s at an acceleration of 4/3 m/s squared begins to brake with a deceleration of magnitude 3 m/s squared determine the time it takes the car to stop

math
 Aug 18, 2014

Best Answer 

 #1
avatar+33661 
+5

You can use the constant acceleration formula: v = u + at

v is  final velocity (0 m/s)

u is initial velocity (20 m/s)

a is acceleration (-4/3 m/s2: the minus sign shows it is decelerating)

t is the time (in seconds)

So:

0 = 20 - (4/3)*t

Rearrange:

(4/3)t = 20

t = 20*3/4

t = 15 seconds

 Aug 18, 2014
 #1
avatar+33661 
+5
Best Answer

You can use the constant acceleration formula: v = u + at

v is  final velocity (0 m/s)

u is initial velocity (20 m/s)

a is acceleration (-4/3 m/s2: the minus sign shows it is decelerating)

t is the time (in seconds)

So:

0 = 20 - (4/3)*t

Rearrange:

(4/3)t = 20

t = 20*3/4

t = 15 seconds

Alan Aug 18, 2014

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