Question

a class assignment requires the building of a solar powered car that will travel at least 10 meters in 10 seconds. each group is given one solar cell for their design. which of these would improve the design the most?
options:

• using a thicker axle.
• adding mass to the design.
• reducing the mass of the design.
• making the size of the car bigger.

pregunta 5
1 puntos
which flow diagram best explains the energy transformations that occur within an automobile running on diesel?
options:

• chemical energy → kinetic energy→ thermal energy
• thermal energy → kinetic energy → chemical energy
• kinetic energy → mechanical energy → thermal energy
• mechanical energy → thermal energy → chemical energy

Explanation:

First Question (Solar - powered car design improvement)

To improve the solar - powered car's performance (travel at least 10 meters in 10 seconds) with one solar cell, we consider the effect of mass on motion. According to Newton's second law ($F = ma$), with a fixed force (from the solar cell), reducing mass ($m$) increases acceleration ($a$), which helps the car move faster. A thicker axle may not significantly improve speed, adding mass slows it down, and making the car bigger usually increases mass. So reducing the mass of the design is the best improvement.

Diesel is a fuel with chemical energy. When diesel is burned in the engine, the chemical energy is first converted into thermal energy (heat) during combustion. Then, this thermal energy is converted into kinetic energy (the energy of motion) to move the automobile. The other options have incorrect energy transformation sequences: thermal energy doesn't convert to chemical energy in a diesel engine, kinetic energy isn't the starting energy, and mechanical energy isn't the initial energy source.

Answer:

Reducing the mass of the design.

Second Question (Energy transformations in a diesel - powered automobile)