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A certain class of lamp takes 0.45A at 220V. How many such lamp can be run for an expenditure of power equal to 1 1/3 horsepower?
Which of the following descriptions of an object is not equivalent to the others?
A.the object is at rest
B.The forces on the object are balanced
C. The velocity of the object is constant
D. The acceleration of the object is 0
A certain copper wire has a resistance of 25 ohms at 10 degrees Celsius. Take the temperature coefficient at 10 degrees Celsius to be 0.00405. What must be the maximum operating temperature of the wire if its resistance is to increase by at most 20%.
caculate the linear expansivity of brass of length 120m, that assume a new length of 120.05m when headed through a temperature of 100
A 1000mf capacitor is charged to 10v and 16uf capacitor is charged to 400v.these are then connected in parallel with plates carrying similar charges connected together. Determined the total stored energy before and after joining them. Is final energy the same as the initial energy?
A 1000mf capacitor is charged to 10v and 16uf capacitor is charged to 400v.these are connected in parallel with plates carrying similar charges.Determined the total stored energy before and after joining them.
Find the moment of inertia about the central axis of a disk of radius R and total mass M
Typical backyard ants often create a network of chemical trails for guidance. Extending outward from the nest, a trail branches (bifurcates) repeatedly, with 60° between the branches. If a roaming ant chances upon a trail, it can tell the way to the nest at any branch point: If it is moving away from the nest, it has two choices of path requiring a small turn in its travel direction, either 30° leftward or 30° rightward. If it is moving toward the nest, it has only one such choice. Given figure shows a typical ant trail, with lettered straight sections of 2.0 cm length and symmetric bifurcation of 60°. Path “v” is parallel to the y axis. What are the (a) magnitude and (b) angle (relative to the positive direction of the superimposed x axis) of an ant’s displacement from the nest (find it in the figure) if the ant enters the trail at point A? What are the (c) magnitude and (d) angle if it enters at point B? Nest is located at the end of the segment “w”.
You are driving toward a traffic signal when it turns yellow. Your speed is the legal speed limit of V0 = 55 km/h; your best deceleration rate has the magnitude a = 5.18 m/s2. Your best reaction time to begin braking is T = 0.75 s. To avoid having the front of your car enter the intersection after the light turns red, should you brake
to a stop or continue to move at 55 km/h if the distance to the intersection and the duration of the yellow light are (a) 40 m and 2.8 s, and (b) 32 m and 1.8 s? Give an answer of brake, continue, either (if either strategy works), or neither (if neither strategy works and the yellow duration is inappropriate).
Harvard Bridge, which connects MIT with its fraternities across the Charles River, has a length of 364.4 Smoots plus one ear. The unit of one Smoot is based on the length of Oliver Reed Smoot, Jr., class of 1962, who was carried or dragged length by length across the bridge so that other pledge members of the Lambda Chi Alpha fraternity could mark off (with paint) 1-Smoot lengths along the bridge. The marks have been repainted biannually by fraternity pledges since the initial measurement, usually during times of traffic congestion so that the police cannot easily interfere. (Presumably, the police were originally upset because the Smoot is not an SI base unit, but these days they seem to have accepted the unit.) Figure given below shows three parallel paths, measured in Smoots (S), Willies (W), and Zeldas (Z). What is the length of 50.0 Smoots in (a) Willies and (b) Zeldas?
