Question3. A block is released from rest at the top of a rough ramp. There is significant friction between the block and the ramp, but the block's speed increases as the block slides down the ramp. Which of the following correctly indicates whether the total mechanical energy of the block-Earth system decreases or remains the same, and provides a valid justification? (A) Decreases, because a force external to the system is dissipating energy (B) Decreases, because the gravitational potential energy of the system decreases (C) Stays the same because energy is always conserved (D) Stays the same because gravitational potential energy is converted into kinetic energy
Studdy Solution
STEP 1
1. The block is part of a block-Earth system.
2. The ramp is rough, indicating the presence of friction.
3. The block's speed increases as it slides down the ramp.
4. We need to determine the change in total mechanical energy of the system.
STEP 2
1. Define the components of mechanical energy in the system.
2. Analyze the effect of friction on mechanical energy.
3. Determine whether the total mechanical energy decreases or remains the same.
4. Justify the conclusion based on energy principles.
STEP 3
Mechanical energy in the block-Earth system consists of gravitational potential energy and kinetic energy.
STEP 4
Friction is a non-conservative force that converts mechanical energy into thermal energy, which is not part of the mechanical energy of the system.
STEP 5
Since friction is present, some of the mechanical energy is converted into thermal energy, which means the total mechanical energy of the system decreases.
STEP 6
The correct answer is (A) Decreases, because a force external to the system (friction) is dissipating energy.
The correct choice is:
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