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Suppose that your car consumes a gallon of gasoline in half an hour. What is its rate of chemical energy consumption, in watts and in horsepower?
The average American passenger car or light truck can drive about 20 miles on a gallon of gasoline: we say that its “fuel economy” is 20 miles per gallon. In the rest of the world, fuel economy would be expressed in kilometers per liter. Given that there are 1.6 kilometers in a mile and 3.8 liters in a gallon (approximately), express the fuel economy of the average American passenger vehicle in kilometers per liter
Imagine that you are on a space walk outside a vessel coasting
through interstellar space. You have launched a reference probe that is
perfectly stationary relative to the ship, equipped with precision laser
velocity-measuring devices. A meteoroid approaches at 4.0 m/s, strikes
the ship, and bounces off in exactly the opposite direction at 2.0 m/s.
you grab the meteoroid, take it into the ship, put it into an inertial mass
meter, and find out that it masses 1.0 kg. The ship’s mass is 20,000 kg
without you on board. You know that the impact has caused the space
ship to start moving relative to the probe in the same direction the
meteoroid was originally travelling. What will the probe indicate as thmagnitude of the ship’s post-collision velocity vector?
Two forces 10N and 40N can be combined torive a resultant of
There are expanded isothermally 3 lb/sec of NH, from saturated vapor to the state of 10 psia, 100°F. Determine (a) Q, (b)W (nonflow), (c) W (steady flow with ∆K=0), (d) ∆G, (e) the unavailable part of Q for t= 60°F. See Item B 33.
An adiabatic vessel contains steam at 1025 psia, 750°F. A valve is opened slowly permitting an outflow of steam; it is closed quickly when the steam remaining in the vessel becomes saturated vapor. What fractional part of the original steam remains? Assume that this part underwent a reversible adiabatic expansion.
Imagine that you are on interplanetary vessel coasting through a space to a rendezvous with Neptune. You discover that an immediate course correction is necessary. Otherwise the ship will not fall into orbit around Neptune, but will fly off into interstellar space! Your onboard computers indicate that the ship must gain 100.0m/s of forward speed to get back on course. Suppose the mass of the craft is exactly 2.0 x 10^4 kg. The rocket produce a constant force of 2.500 x 10^4 N.
A. When the rockets are fired, how fast will the ship accelerate?
B. How long will it take for the forward velocity of the ship to increase by the required 100.0m/s?
C. What will be the impulse that produces this course correction?
Discuss whether any work is being done by each of the following agents and, if so, whether the work is positive or negative. Explain briefly.(a) a chicken scratching the ground(b) a person studying(c) a crane lifting a bucket of concrete(d) the gravitational force on the bucket in part (c)(e) the leg muscles of a person in the act of sitting down.
A crate is moving 2m along horizontal floor at a constant speed by a force of 50N which makes an angle of 30° above the horizontal. How much work is done on the crate by the force? Show complete solution.
A 0.2kg is drag 0.5m upward with a uniform velocity along a plane inclined 30° with the horizontal by a force parallel to the incline. The coefficient of kinetic friction between the object and the plane is 0.25. How much work is done by the applied force? Show complete solution.
