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allsm [11]
3 years ago
11

An automobile approaches a barrier at a speed of 20 m/s along a level road. The driver locks the brakes at a distance of 50 m fr

om the barrier. What minimum coefficient of kinetic friction is required to stop the automobile before it hits the barrier?
Physics
1 answer:
AleksAgata [21]3 years ago
5 0

Answer:

μ = 0.408

Explanation:

given,

speed of the automobile (u)= 20 m/s

distance = 50 m

final velocity  (v) = 0 m/s

kinetic friction = ?

we know that,

v² = u² + 2 a s

0 = 20² + 2 × a × 50

a = \dfrac{400}{2\times 50}

a = 4 m/s²

We know

F = ma = μN

ma = μ mg

a = μ g

\mu = \dfrac{a}{g}

\mu = \dfrac{4}{9.81}

μ = 0.408

hence, Kinetic friction require to stop the automobile before it hit barrier is 0.408

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Answer:

T = 0.225 s

Explanation:

The speed of a projectile at the highest point of its motion is the horizontal speed of the projectile. Considering the horizontal motion with negligible air resistance, we can use the following formula:

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