Solving Friction and Incline Problems: Get Answers Here!

[Elvis]

Hi !

Can anyone help me ?

Problem :
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1- A coffee cup on the dashboard of a car slides forward on the dash when the driver decelerates from 40 km/h to rest in 3.5 s or less, but not if he decelerates in a longer time. What is the coefficient of static friction between the cup and the dash ?
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2- An 18-kg box is released on a 37*(grade) incline and accelerates down the incline at 0.270 m/s(square). Find the friction force impeding its motion. How large is the coefficient of friction
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Thanks !

 

[quantumdude]

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