Question

a block of mass 2 kg slides down an inclined plane. the block starts at a vertical height of 3 meter above the bottom of the incline, with a speed of 5 m/s and reaches bottom with 7 m/s how much energy is lost due to friction??

Answer 1

To solve this problem, we need to use the conservation of energy principle. The potential energy of the block at the top of the incline is converted into kinetic energy as it slides down the incline. However, some of this energy is lost due to friction between the block and the incline. Let's start by calculating the potential energy of the block at the top of the incline:

• Potential energy at the top = mgh

where m is the mass of the block, g is the acceleration due to gravity, and h is the height of the incline.

• Potential energy at the top = 2 kg * 9.81 m/s^2 * 3 m

• Potential energy at the top = 58.86 J

Next, we can calculate the kinetic energy of the block at the bottom of the incline:

• Kinetic energy at the bottom = (1/2) * m * v^2

where m is the mass of the block and v is its velocity at the bottom of the incline.

• Kinetic energy at the bottom = (1/2) * 2 kg * (7 m/s)^2

• Kinetic energy at the bottom = 49 J

The energy lost due to friction is simply the difference between the potential energy at the top and the kinetic energy at the bottom:

• Energy lost due to friction = Potential energy at the top - Kinetic energy at the bottom
  Energy lost due to friction = 58.86 J - 49 J
  Energy lost due to friction = 9.86 J

Therefore, the energy lost due to friction is 9.86 J.