Using energy considerations and assuming negligible air resistance, show that a rock thrown from a bridge 20.0 m above water with an initial speed of 15.0 m/s strikes the water with a speed of 24.8 m/s independent of the direction thrown.

Q: Coal is lifted out of a mine a vertical distance of 50 m by an engine that supplies 500 W to a…

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Q: A crane lifts a 650 kg beam vertically upward 9.6 m and then swings it westward 18 m. How much work…

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Q: A 261 kg ball from a demolition machine is propelled sideways until it is 4.83 m above its lowest…

A: Given : Mass of a ball (m) = 261 kg Height (h) = 4.83 m

Q: Suppose the ski patrol lowers a rescue sled carrying an injured skiier, with a combined mass of 97.5…

A: Normal force on sled is mgcosθ Friction force: Substitute mgcosθ for  in above equation. Here; =…

Q: The work done by a force that varies in magnitude can be obtained from which of the following…

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Q: Find the work done by 45N force in pulling the suitcase at an angle of 50d egrees with respect to…

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Q: Using the principle of conservation of mechanical energy, calculate the maximum height achieved by a…

A: Weight of ball = 5 N Velocity of ball = 12 m/s Maximum height =?

Q: A fully loaded, slow-moving freight elevator has a cab with a total mass of 1600 kg, which is…

A: Given:-         Total mass  M=1600 kg        Distance to cover  d=39 m        Time taken  t=2.2…

Q: A bus of mass 1000 kg with an initial velocity of 40 m/s starts up a hill and coasts upward with no…

A: Given : Initial Velocity (  u ) = 40 m/s Mass ( m ) = 1000 kg The height achieved when it stops ( h…

Q: What average mechanical power (in W) must a 61.5 kg mountain climber generate to climb to the summit…

A: The mechanical power of the climber can be found as, Here, W and t represent the work-done and…

Q: An object of mass 7.39 kg is moving with an initial kinetic energy 394 Joules. If the object…

A: Given data: Mass of the object, m=7.39 kg Initial kinetics energy of the object, K.Ei=394 J…

Q: How much work is done on a downhill skier by an average breaking force of 813 newtons to stop her in…

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Q: The elevator with a mass of 200 kg with an input power of 4.5 kW with a constant speed, takes 2…

A: The elevator has a mass of 200 kg. Let M=200 kg. The elevator carries 2 persons, 50 kg each, from…

Q: What would be the power output in hp of a 1750 kg car if it can ascend to the top of a 285 m high…

A: Take the bottom of the hill to be at height zero. The potential energy of the car at the bottom of…

Q: Calculate the power output of a 15 mg fly as it walks straight up a windowpane at 2.0 cm/s.

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Q: Suppose a 51.5-kg woman does 50 deep knee bends in which her center of mass is lowered and raised…

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Q: Calculate the work needed to lift a 20 kg sack of rice vertically at 6-5 m ?

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Q: You drag your 30 kg suitcase 1200 m thru the Chicago airport at essentially constant velocity 2.0…

A: Given: Mass, M = 30kg Distance , s= 1200m Velocity, v = 2.0m/s Force, F = 90N, 20o westward

Q: An advertisement claims that a 1000 kg car can accelerate from rest to a speed of 20 m/s in a time…

A: mass = 1000kg v1= 0m/s;    v2=20m/s t= 5sec. K.E1= 0  (car starts from rest) K.E2= (1/2)* 1000*…

Q: A 5.0 N projectile leaves the ground with a kinetic energy of 220 J. At the highest point in its…

A: The difference between the kinetic energies is,

Q: A baseball of mass 350 g is hit at home plate with a speed of 50 m/s. When it lands in a seat in the…

A:

Q: Show that about 786 W of power is expended when a 500-N barbell is lifted 2.2 m above the floor in…

A: The expression for the power is,

Q: Using energy considerations and assuming negligible air resistance, show that a rock thrown from a…

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Q: A 1300-kg elevator carries a maximum load of 750 kg. A constant frictional force of 3000 N retards…

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Q: You reach out of a window 15 m above the ground and toss a ball straight up with a speed of 10 m/s.…

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Q: Find his power output, in watts, for the work he does against the gravitational force and air…

A: a) Analyze the following figure. Since the skier is moving at a constant speed, its acceleration…

Q: An electric motor with an output of 15kW provides power for the elevator of a six storey building.…

A: The work done by the motor is, W=F×d                                       F=mg,d=displacement…

Q: A 55-kg marathon runner runs up the stairs to the top of Taguig’s 318-m Grand Hyatt Manila, the…

A: Mass of the runner M=55 kg The height reached h=318 m The time taken t=20 minutes=20×60 s=1200 s…

Q: How much work must you do to push a 11.0 kg block of steel across a steel table (μk=0.6)at a steady…

A: a) The required work done is,

Q: that

A: Given, Mass(M)=13 kg. Displacement=65 cm=65/100 m=0.65 m. g=9.8 m/s²

Q: A 55 kg motorcyclist is flying through the air at 72 km/h at the apex of the jump 8.3 m above the…

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Q: What average mechanical power must a 70.0 - kg mountainclimber generate to climb to the summit of a…

A: Using Work-Energy theorem,

Q: A car accelerates uniformly from rest to 20.0 m/s in 5.6 s along a level stretch of road. Ignoring…

A: Given that, The initial speed of the car, u = 0 Final speed of the car, v = 20 m/s Time, t = 5.6 s…

Q: The surfer in the photo is catching a wave. Suppose she starts at the top of the wave with a speed…

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Q: The power delivered by a constant  force is given by P=F⃗·v⃗,  The power exerted by gravity as it…

A: The power delivered by the force is given by,

Q: An object is thrown up in the air with an initial speed 21 m/s. At what height, in meters, its…

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Q: Find the work done in joules by gravity as an object of the mass m 5 kg is raised up at constant…

A: Mass of object m = 5 kg Initial height h1 = 26 m Final height h2 = 69 m g = 10 m/s²

Q: While cruising along a level ground in a one horse open sleigh at 4.0 m/s, Santa cracks the whip and…

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Q: Suppose the ski patrol lowers a rescue sled carrying an injured skiier, with a combined mass of 77.5…

A: In this question we have to answer how much work, in joules, is done by the rope on the sled over…

Q: A bag of wheat weight 130 kg. To what height should it be raised so that potential energy is 150 J ?…

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Q: The 2018 Pyeongchang gold medalist winner in a large hill ski jumping discipline, Kamil Stoch,…

A: Applying conservation of energy to calculate the final speed of the man…

Q: Suppose a 825-kg car can produce a useful power output of 45.5 hp (1 hp = 746 W). How long, in…

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