Finding kinetic energy from force, distance, mass

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SUMMARY

The discussion focuses on calculating the kinetic energy of a 1.85-kg rock falling in a pond with a depth of 1.00 m, while experiencing a constant upward force of 3.70 N due to water resistance. The key equations involved include the kinetic energy formula, K = 1/2 mv², and the need to determine the velocity (V) of the rock at various depths (0, 0.5, and 1 m). Participants agree that finding the acceleration is essential for calculating the velocity, which is necessary to derive the kinetic energy.

PREREQUISITES
  • Understanding of Newton's second law of motion
  • Familiarity with the concepts of kinetic energy and gravitational potential energy
  • Basic knowledge of forces and work-energy principles
  • Ability to perform calculations involving mass, force, and acceleration
NEXT STEPS
  • Calculate acceleration using Newton's second law: F = ma
  • Determine the velocity of the rock at each specified depth
  • Apply the kinetic energy formula to find K at different depths
  • Explore the concept of nonconservative work done by water resistance
USEFUL FOR

Students studying physics, particularly those focusing on mechanics, as well as educators and tutors assisting with homework related to energy calculations and forces.

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Homework Statement


A 1.85-kg rock is released from rest at the surface of a pond 1.00 m deep. As the rock falls, a constant upward force of 3.70 N is exerted on it by water resistance. Calculate the nonconservative work, Wnc, done by water resistance on the rock, the gravitational potential energy of the system, U, the kinetic energy of the rock, K, and the total mechanical energy of the system, E, for the following depths below the water's surface. Let y = 0 be at the bottom of the pond.

I need to find kinetic energy for three different distances, 0, .5, and 1.

Homework Equations


Kinetic energy= 1/2mv^2


The Attempt at a Solution


I understand the equation. however do not know how to get V. do i need to find acceleration and go from there? or is there a simpler method?
 
Physics news on Phys.org
Yes, finding the acceleration would be a great place to start
 

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