physics

4.80-kg watermelon is dropped (zero initial speed) from the roof of a 25.0-m-tall building. a) Calculate the work done by gravity on the watermelon during its displacement from the roof to the ground. b) What is the kinetic energy of the watermelon just before it strikes the ground? You can ignore air resistance.

  1. 👍
  2. 👎
  3. 👁
  1. Work is force times distance

    Force is mass times acceleration

    Your acceleration is g=9.8 m/s, mass is 4.8 kg

    So force is 9.8*4.8= 47 kg m/s, and distance is 25m

    (a) Work then becomes 25*47=1176 J

    Kinetic energy is the same as work, since you don't have any air resistance. KE=1176J

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics

    A 4.20-kg watermelon is dropped from rest from the roof of a 28.0-m -tall building and feels no appreciable air resistance. Calculate the work done by gravity on the watermelon during its displacement from the roof to the ground.

  2. physics

    A stone is dropped from the roof of a tall building. A person measures the speed of the stone to be 49 m/s when it hits the ground. What is the height of the building?

  3. physics

    A stuntman plans to run across a roof top and then horizontally off it to a land on the roof of the next building . The roof of the next building is 4.8 m below the first one and 6.2 m away from it . Can he make the jump if his

  4. Science

    A ball is thrown horizontally from the roof of building 50.m tall and lands 45m from the base. What was the balls initial speed

  1. Phisycs

    Lake Point Tower in Chicago is the tallest apartment building in the United States (although not the tallest building in which there are apartments).Suppose you take the elevator from street level to the roof of the building.The

  2. Physics

    You are walking around your neighborhood and you see a child on top of a roof of a building kick a soccer ball. The soccer ball is kicked at 41° from the edge of the building with an initial velocity of 21 m/s and lands 59 meters

  3. physics

    As a science project, you drop a watermelon off the top of the Empire State Building, 320 m above the sidewalk. It so happens that Superman flies by at the instant you release the watermelon. Superman is headed straight down with

  4. physics

    a ball is thrown horizontally -> from the roof of a building 45.0 meters tall and lands 24.0 meters from the base. what was the balls initial speed? OTHER QUESTION a shotputter throws the shot with an initial speed of 15.5 m/s @

  1. physic

    A stone is dropped from the roof of a high building. A second stone is dropped 1.00s laterHow far apart are the stones when the second one has reached a speed of 12.0m/s ?

  2. physics

    A brick is released with no initial speed from the roof of a building and strikes the ground in 1.50 {s}, encountering no appreciable air drag. A. How tall, in meters, is the building? B.How fast is the brick moving just before it

  3. Algebra

    A watermelon is dropped from the top of a building The height of the watermelon above the sidewalk is given by h(t)=-16t^2+240 with t representing number of seconds How many seconds does it take for the watermelon to hit the

  4. Physics

    A hammer is thrown horizontally from the flat roof of a tall building at a velocity of 10m/s and hits the ground below after 5 seconds. (a) How high is the roof? (b) How far from the building does it land.

You can view more similar questions or ask a new question.