A large box of mass Mis pulled across a horizontal, frictionless surface by a horizontal rope with tension T. A small box of mass m sits on top of the large box. The coefficients of static and kinetic friction between the two boxes are μsand μk, respectively. Find an expression for the maximum tension Tmaxfor which the small box rides on top of the large box without slipping.

Short Answer

Expert verified

The expression isTmax=μsg(M+m)

Step by step solution

01

Step 1. The small box acceleration

First we isolate the F.B.D of each mass,

we start with the smaller one who is on top of the bigger box

The small box need to accelerate toto induce a force to make it slip

02

Step 2. Acceleration needed for the small box to start slipping 

Now let take the F.B.D of the large box, the large box is moving in a frictionless surface

FxM=0Tmax-ma=0Tmax=mtotalamax

We will use the acceleration needed for the small box to start slipping, because the reference frame of the small box is the large box

Tmax=(M+m)(μsg)Tmax=μsg(M+m)

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Sam, whose mass is 75kg, takes off across level snow on his jet-powered skis. The skis have a thrust of 200N and a coefficient of kinetic friction on snow of 0.10. Unfortunately, the skis run out of fuel after only10 s.

a. What is Sam’s top speed?

b. How far has Sam traveled when he finally coasts to a stop?

A construction worker with a weight of 850N stands on a roof that is sloped at 20°. What is the magnitude of the normal force of the roof on the worker?

Zach, whose mass is 80 kg, is in an elevator descending at 10 m/s. The elevator takes 3.0 s to brake to a stop at the first floor.

a. What is Zach’s weight before the elevator starts braking?

b. What is Zach’s weight while the elevator is braking?

A 1500 kg car skids to a halt on a wet road where μk=0.50. How fast was the car traveling if it leaves role="math" localid="1648126746388" 65m-long skid marks?

Large objects have inertia and tend to keep moving-Newton's BI0 first law. Life is very different for small microorganisms that swim through water. For them, drag forces are so large that they instantly stop, without coasting, if they cease their swimming motion. To swim at constant speed, they must exert a constant propulsion force by rotating corkscrew-like flagella or beating hair-like cilia. The quadratic model of drag of Equation 6.15fails for very small particles. Instead, a small object moving in liquid experiences a linear drag force, Fdrag=(bv, the direction opposite the motion), where bis a constant. For a sphere of radius R, the drag constant can be shown to be b=6πηR, where ηis the viscosity of the liquid. Water at 20Chas viscosity 1.0×103Ns/m2.

a. A paramecium is about 100μmlong. If it's modeled as a sphere, how much propulsion force must it exert to swim at a typical speed of 1.0mm/s? How about the propulsion force of a 2.0-μm-diameter E. coli bacterium swimming at 30μm/s?

b. The propulsion forces are very small, but so are the organisms. To judge whether the propulsion force is large or small relative to the organism, compute the acceleration that the propulsion force could give each organism if there were no drag. The density of both organisms is the same as that of water, 1000kg/m3.

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free