A woman places her briefcase on the backseat of her car. As she drives to work,

Question

A woman places her briefcase on the backseat of her car. As she drives to work, the car negotiates an unbanked curve in the road that can be regarded as an arc of a circle of radius 62.0 m. While on the curve, the speed of the car is 15.0 m/s at the instant the briefcase starts to slide across the backseat toward the side of the car. (a) What force causes the centripetal acceleration of the briefcase when it is stationary relative to the car? Under what condition does the briefcase begin to move relative to the car? (b) What is the coefficient of static friction between the briefcase and seat surface?

Explanation / Answer

Here given

Velocity, (v) = 15m/s

Radius, r = 62m

Angular velocity, = v/r = 15/ 62 = 0.29

Centripetal acceleration = v2/r = 3.63 m/s2

Centripetal force on car = mass x centripetal acceleration = 3.63x mass

The force which causes the centripetal acceleration of the briefcase when it is stationary relative to the car is called pseudo force, its value is equal to the centripetal force on car but in opposite direction.

b) = coefficient of friction

here

mv2/r = mg

v2/r =g

= v2( r g)

= (15)2/ (62 x 9.81)

= 0.3699

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.