Question

A car traveling at 4 m/s can be stopped at a didtance of 4 m by applying break. If the same car is traveling at 10m/s then minimum stopping distance will be

Answer 1

Answer:

Given:

Initial velocity = 4 m/s

Distance to stop = 4 m

To find:

Distance to stop if the car is moving at 10 m/s initial velocity

Concept:

First we need to find out the retardation produced by the brakes. Using the value of retardation, we can solve the equations of kinematics to get distance.

Calculation:

1st case:

v² = u² + 2as

=> 0 = 4² + 2 × a × 4

=> a = - 2 m/s²

Now , 2nd case:

v² = u² + 2as

=> 0 = 10² + 2 × (-2) × s

=> s = 25m

So the stopping distance will be

25 m.

Answer 2

AnswEr :

⋆ First Condition :

• Initial Velocity ( u ) = 4 m/s
• Final Velocity ( v ) = 0 m/s [As when brakes get applied then, velocity will be 0 m/s]
• Distance to Stop ( s ) = 4 m

• Using the third Equation of Motion :

⇒ v² - u² = 2as

• plugging the values

⇒ ( 0 )² - ( 4 )² = 2a × 4

⇒ 0 - 16 = 8a

⇒ - 16 = 8a

⇒ a = - 16 /8

⇒ a = - 2 m/s²

∴ we observe the Retardation of 2 m/s².

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⋆ Second Condition :

• Initial Velocity ( u ) = 10 m/s
• Final Velocity ( v ) = 0 m/s
• Acceleration ( a ) = - 2 m/s²
• Distance ( s ) = ?

• Using the third Equation of Motion :

⇒ v² - u² = 2as

• plugging the values

⇒ ( 0 )² - ( 10 )² = 2 × ( - 2 ) × s

⇒ 0 - 100 = - 4s

⇒ - 100 = - 4s

⇒ s = - 100 /- 4

⇒ s = 25 m

∴ Car will stop after 25 m after brakes.