Mastering Physics Solutions: Problem 6.37

Mastering Physics Solutions: Problem 6.37

On March 16, 2014, in Chapter 05: Work and Energy, by Mastering Physics Solutions

Part A = 8.075 m/s
Part B = 0.255 m

What is his speed as he lands on the trampoline, 2.2 m below his jump off point?
If the trampoline behaves like a spring with spring stiffness constant 7.1 * 10^4 N/m , how far does he depress it? Any depression of the trampoline from equilibrium is to be taken as a negative distance.

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Mastering Physics Solutions: Energy Required to Lift a Heavy Box

Mastering Physics Solutions: Energy Required to Lift a Heavy Box

On March 2, 2013, in Chapter 05: Work and Energy, by Mastering Physics Solutions

Part A = F = mg/2
Part B = Wd / Wp = 1.00

What is the magnitude F of the upward force you must apply to the rope to start raising the box with constant velocity?

What is Wd / Wp, the ratio of the work done lifting the box directly to the work done lifting the box with a pulley?

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Mastering Physics Solutions: Where’s the Energy?

Mastering Physics Solutions: Where’s the Energy?

On March 1, 2013, in Chapter 05: Work and Energy, by Mastering Physics Solutions

Part A = smooth
Part B = a distance 2h/3 above the floor
Part C = -2mgh/3
Part D = -mgh
Part E = 1/2mvi^2 + mghi = 1/2mvf^2 + mghf
Part F = K increases; U decreases; E stays the same
Part G = sqrt(v^2 + 2gh)
Part H = 1/2mvi^2 + Wnc = 1/2mvf^2
Part I = K decreases; U stays the same; E decreases
Part J = friction
Part K = 0.5mv^2 + mgh

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Mastering Physics Solutions: Baby Bounce with a Hooke

Mastering Physics Solutions: Baby Bounce with a Hooke

On February 22, 2013, in Chapter 05: Work and Energy, by Mastering Physics Solutions

Part A = k = 2.5/0.005
Part B = 0.37 m Click to use the calculator/solver for this part of the problem

The following chart and accompanying graph depict an experiment to determine the spring constant for a baby bouncer.

What is the spring constant of the spring being tested for the baby bouncer?

One of the greatest difficulties with setting up the baby bouncer is determining the right height above the floor so that the child can push off and bounce. Knowledge of physics can be really helpful here.

If the spring constant k = 5.0 * 10^2 N, the baby has a mass m = 11 kg, and the baby’s legs reach a distance d = 0.15 m from the bouncer, what should be the height of the “empty” bouncer above the floor?

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Mastering Physics Solutions: Delivering Rescue Supplies

Mastering Physics Solutions: Delivering Rescue Supplies

On February 22, 2013, in Chapter 05: Work and Energy, by Mastering Physics Solutions

Part A = v = sqrt(2gh(μkcot(α) + 1))

You are a member of an alpine rescue team and must project a box of supplies, with mass m, up an incline of constant slope angle α so that it reaches a stranded skier who is a vertical distance h above the bottom of the incline. The incline is slippery, but there is some friction present, with kinetic friction coefficient μk.

Use the work-energy theorem to calculate the minimum speed v that you must give the box at the bottom of the incline so that it will reach the skier.

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Mastering Physics Solutions: Exercise 13.12

Mastering Physics Solutions: Exercise 13.12

On December 27, 2011, in Chapter 13: Vibrations and Waves, by Mastering Physics Solutions

Part A = 1.2m/s Click to use the calculator/solver for this part of the problem
Part B = at the equilibrium position
Part C = 1.0m/s Click to use the calculator/solver for this part of the problem

A mass-spring system is in SHM in the horizontal direction. If the mass is 0.25 kg, the spring constant is 15 N/m, and the amplitude is 15 cm, what is the maximum speed of the mass? Where does this occur? What is the speed at a half-amplitude position?

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