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    Heat contained in the Great Lakes

    Homework Statement the largest of the Great Lakes, Lake Superior contains 1.2*10^16kg of fresh water, which has a specific capacity of 4186J/kg*C and a latent heat of fusion of 3.33*10^5J/kg. a.) If Lake Superior were still liquid at 0C, how much energy would need to be removed from the lake...
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    Momentum of pendulum after hitting it with bullet

    Homework Statement An 9 g bullet is fired into a 2.5 kg pendulum bob which is initially at rest and becomes embedded in the bob. The pendulum then rises a vertical distance of 6cm. What was the initial speed of the bullet? What will be the kinetic energy of the pendulum when the pendulum...
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    Work and force

    Homework Statement a 50 kg diver steps off a diving board and drops straight down into the water. The water provides an upward average net force of 1500 N. If the diver comes to rest 5.0m below the water's surface, what is the total distance between the diving board and the diver's stopping...
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    Work total

    Homework Statement a 2.1*10^3 kg car starts from rest at the top of a driveway that is sloped at an angle of 20 with the horizontal. An average friction force of 4.0*10^3 N impedes the car's motion so that the car's speed at the bottom of the driveway is 3.8m/s., What is the length of the...
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    Mistake in solving for work in physics?

    Homework Statement a student wearing a frictionless in-line skates on a horizontal surface is pushed by a friend with a constant force of 45N. How far must the student be pushed, starting from rest, so that her final kinetic energy is 352J? Homework Equations The Attempt at a...
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    How long does the ball take to hit the ground?

    Homework Statement a 3 kg ball is dropped from rest from the roof on a building 176.4 m high. While the ball is falling, a horizontal wind exerts a constant force of 12 N on the ball? Part 1) How long does the ball take to hit the ground? Part 2) How far from the building does the ball hit the...
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    Force q.

    Homework Statement a 5.1*10^2 kg bundle of bricks is pulled up a ramp at an incline of 14 degrees to a construction site. the force needed to move the bricks up the ramp is 4.1*10^3 N. What is the coefficient of static fiction between the bricks and the ramp? Homework Equations well...
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    What would be the truck's skidding distance?

    Homework Statement use to answer 1 and 2. A truck driver slams on the brakes and skids to a stop through a displacement of x. 1.) if the truck's mass doubles, find the truck's skidding distance in terms of x.(hint:increasing the mass increases the normal force.) a. x/4 b. x c. 2x d. 4x...
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    Force homework problem help

    Homework Statement a.) a box slides down a 30 degree ramp with an acceleration of 1.20 m/s^2. Determine the kinetic friction between the box and the ramp. Homework Equations The Attempt at a Solution the equation is uk=Fk/Fn but they did not provide me with atleast one force or...
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    How to draw the angles to find force

    Homework Statement http://img150.imageshack.us/my.php?image=toottzx0.png Homework Equations I have the picture and everything but i just need help with the angles. Like i am a bit confused about how to draw the angles and stuff please help. The Attempt at a Solution
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    Coordinate system for specifying the precise location of objects in space?

    Homework Statement which of the following is a coordinate system for specifying the precise location of objects in space? a. frame of reference b. diagram c. x-axis d. y-axis Homework Equations The Attempt at a Solution I thought it would be a diagram since it would use vectors...
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    Find the initial velocity if the angle, horizontal distance and the vertical distance is given?

    Homework Statement how can you find the initial velocity if the angle, horizontal distance and the vertical distance is given? Homework Equations The Attempt at a Solution every equation i use gives me a different answer so i have no clue which one is correct
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    Projectile motion of a fish

    Homework Statement salmon often jump waterfalls to reach their breeding grounds. One salmon starts 2m from a waterfall that is .55m tall and jumps at an angle of 32degrees. what must be the salmon's minimum speed to reach the waterfall? Homework Equations The Attempt at a Solution...
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    Projectile motion of a baseball problem

    Homework Statement a baseball is thrown at an angle of 25 degrees relative to the ground at a speed of 23.0m/s. If the ball was caught 42 m from the thrower, how long was it in the air? how high did the ball travel before being caught? Homework Equations The Attempt at a Solution...
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    Flying between aircraft carriers - vectors

    Homework Statement You are a pilot on an aircraft carrier. You must fly to another aircraft carrier, now 1450 km at 45 degree of your position, moving at 56 km/hr due east. The wind is blowing from the south at 72 km/hr. Calculate the heading and airspeed needed to reach the carrier 2.5 hour...
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    2x distance

    Homework Statement two students are standing on a fire escape, one twice as high as the other. simultaneously, each drops a ball. if the first ball strikes the ground at time t1 when willt he second ball strike the ground? A)t2=4t1 B)t2=5/4t1 C)t2=2t1 D)t2=squareroot of 2 times t1...
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    Acceleration of object and displacement after given time

    Homework Statement a kitten pushes a ball of yarn rolling toward it at 1.00 cm/s with its nose, displacing the ball of yarn 17.5 cm in the opposite direction in 2.00 s. What is the acceleration of the ball of yarn? Homework Equations The Attempt at a Solution i used...
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    Velocity of ball problem

    Homework Statement ball is thrown upward from the ground with an initial speed of 25m/s; at the same instant a ball is dropped from rest from a building 15m high. After how long will the balls be at the same height? Homework Equations The Attempt at a Solution well the first ball...
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    Simple velocity question

    in a race, a tortoise runs at 10cm/s and hare runs at 200cm/s. both start at the same time, but the hare stops to rest for 2.00 min. The tortoise wins by 20.0cm. Part 1) At what time does the tortoise finish the line? Part 2) What is the length of the race? I would really appreciate it if you...
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