الشغل والطاقة

قوانين الشغل والطاقة

المقالات في الفئة الشغل والطاقة
الاسم
A 2000-kg airplane flies at 343 m/s. What is its kinetic energy?
A tall sailing ship (m = 1.43 x 10^4 kg) is initially at rest. A steady wind blows at the 60.0° angle shown in the diagram and moves the ship forward a distance of 850 km. The ships final speed is 9.0 m/s.What is the average force of the wind?
A rifle fires a 4.0-g bullet at a velocity of 950 m/s. If the length of the rifle barrel is 1.01 m, then what force does the rifle exert on the bullet?
An archer pulls a bowstring back a distance of 20 cm with an average force of 75 N. The arrow has a mass of 20.0 g. When he releases the string, what is the velocity of the arrow when it leaves the bow?
A mover uses a pulley system to lift a grand piano with a mass of 500 kg from the ground to a height of 10 m. What is the change in the pianos gravitational potential energy?
Spring 1 is stretched and stores 2 J of elastic potential energy. An identical spring, Spring 2, is stretched and stores 18 J of elastic potential energy. What is the ratio of the displacement of Spring 2 to the displacement of Spring 1?
A man pushes a 100-kg box with a horizontal force of 100 N across a floor for a distance of 60 m in 2 min. What is his power?
A 70-kg man runs at a constant velocity of 2 m/s. What is his kinetic energy?
A 1000-kg car traveling at 30 m/s skids 10 m before it stops. What magnitude of force is the frictional force on the car?
How much work is done to accelerate a 5-kg object from 6 m/s to a speed of 12 m/s?

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