1. A box is lying on a conveyor belt, which is positioned at an angle ? to the h

Question

1. A box is lying on a conveyor belt, which is positioned at an angle ? to the horizontal. The coefficient of friction between the box and the conveyor belt is ?. The conveyor belt starts moving upwards. Find the maximum possible acceleration of the conveyor belt for which the box still would not slip. (Give a symbolic answer.)

2. Ice on a highway decreases the coefficient of friction by a factor of 10 (i.e. ?ice=0.1?). By what factor do you need to reduce the speed of your car so that the braking distance on the icy patch is the same as on a regular road? Hint: introduce the speed of the car, v, and solve the problem symbolically for vice/v.

Explanation / Answer

1) mgsin(alpha)+ma=mu*mgcos(alpha)

==> a=mu*gcos(alpha)-g*sin(alpha)

2) a_ice=0.1*a

v^2=2*a*s

since we want same s

so v^2 is propotional to a

v_ice=sqrt(0.1)*v

==>v_ice=0.316*v

==>v_ice/v=0.316

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

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