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A cyclist is riding his bike up a mountain trail. When he starts up the trail, he is going 8 m/s. As the trail gets steeper, he slows to 3 m/s in 1 minute. What is the cyclist's acceleration?Felipe drives his car at a velocity of 28 m/s. He applies the brake, which slows the vehicle down at a rate of 6.4 m/s2 and causes it to slow to a stop. How long does it take for the car to stop? Round your answer to the nearest tenth.

Respuesta :

Answer:

a)   a = - 0.0833 m / s²,  b)   t = 4.4 s

Explanation:

a) this is a kinematics exercise where the acceleration is along the inclined plane

         v = v₀ - a t

         a = v₀ - v / t

         a = 3 - 8/60

         a = - 0.0833 m / s²

b) in this case the final velocity is zero

         v = v₀ - a t

         0 = v₀ - at

         t = v₀ / a

         t = 28 / 6.4

         t = 4.375 s

         t = 4.4 s