Chapter 6: Q6-6P (page 138)
(II) Estimate the work you do to mow a lawn 10 m by 20 m with a 50-cm-wide mower. Assume you push with a force of about 15 N.
Short Answer
The obtained value of work done is 6000 J.
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 6: Q6-6P (page 138)
(II) Estimate the work you do to mow a lawn 10 m by 20 m with a 50-cm-wide mower. Assume you push with a force of about 15 N.
The obtained value of work done is 6000 J.
All the tools & learning materials you need for study success - in one app.
Get started for free
Why is it tiring to push hard against a solid wall even though you are doing no work?
(II) Chris jumps off a bridge with a bungee cord (a heavy stretchable cord) tied around his ankle, Fig. 6鈥42. He falls for 15 m before the bungee cord begins to stretch. Chris鈥檚 mass is 75 kg and we assume the cord obeys Hooke鈥檚 law,with If we neglect air resistance, estimate what distance dbelow the bridge Chris鈥檚 foot will be before coming to a stop. Ignore the mass of the cord (not realistic, however) and treat Chris as a particle.

FIGURE 6鈥42Problem 41. (a) Bungeejumper about to jump. (b) Bungee cord at itsunstretched length.(c) Maximum stretchof cord.
Suppose you lift a suitcase from the floor to a table. The work you do on the suitcase depends on which of the following: (a) whether you lift it straight up or along a more complicated path, (b) the time the lifting takes, (c) the height of the table, and (d) the weight of the suitcase?
Two identical arrows, one with twice the speed of the other, are fired into a bale of hay. Assuming the hay exerts a constant 鈥渇rictional鈥 force on the arrows, the faster arrow will penetrate how much farther than the slower arrow? Explain.
The energy transformations in pole vaulting and archery are discussed in this chapter, in a similar fashion, discuss the energy transformations related to: (a) hitting a golf ball; (b) serving a tennis ball; and (c) shooting a basket in basketball.
What do you think about this solution?
We value your feedback to improve our textbook solutions.