الشغل والطاقة

Work and Energy

Work and Energy

قوانين الشغل والطاقة
الفلاتر
المقالات في الفئة الشغل والطاقة
الاسم
A marksman fires a 7.5-g bullet from a 1.2-kg handgun. The bullet strikes a target and generates 500 J of thermal energy as it stops. If the length of the gun barrel is 125 mm, then how much force did the handgun exert on the bullet?
A 2700-kg cannon fires an 11-kg cannonball. The length of the cannons barrel is 2.44 m. If the powder produces 2.25 X 10^4 N of force, what is the velocity of the cannonball as it leaves the barrel?
A 750-kg glider is flying level at 100.0 m/s. A tailwind blows constantly for 1200 m, and the gliders speed increases to 120 m/s. What is the approximate force of the tailwind?
A man pushes a lawn mower with a handle at an angle of 60° to the horizontal. He applies a constant 20-N force along the axis of the handle and moves the lawn mower a horizontal distance of 100 m in 5 min. What is the mans power output?
A constant net force of 500 N moves a 1000-kg car 100 m. If the car was initially at rest, then what is the cars final velocity?
A boy pulls a 10-kg box across an ice rink for a distance of 50 m. He exerts a constant force of 10 N on a rope attached to the box at an angle of 60°. How much work has he done on the box?
Two cannons fire identical cannonballs with the same amount of powder. The barrel of Cannon 2 is twice as long as the barrel of Cannon 1. How does the velocity of a cannonball fired from Cannon 2 compare with that of the ball fired from Cannon 1?
Two cars skid to a stop. How does the skid distance of a 100-kg car moving at 30 miles per hour compare to the skid distance of a 50-kg car moving at 15 miles per hour?
What happens to the kinetic energy of a car if its speed is doubled?
A 2000-kg airplane flies at 343 m/s. What is its kinetic energy?