1.1.1 - Energy, Power, and Transportation Technologies

What is the formula for calculating kinetic energy?

• KE = mgh

• KE = ½ mv^2

• KE = mv^2

• KE = 2mv

Answer explanation

The correct formula for calculating kinetic energy (KE) is KE = ½ mv², where m is mass and v is velocity. The other options represent different physical concepts, not kinetic energy.

Which type of energy is stored based on an object's position or condition?

• Kinetic Energy

• Thermal Energy

• Potential Energy

• Chemical Energy

Answer explanation

Potential energy is the energy stored in an object due to its position or condition, such as an object at height or a compressed spring. This distinguishes it from kinetic, thermal, and chemical energy, which are related to motion, heat, and chemical bonds.

What does the 'm' represent in the formula for kinetic energy?

• Mass of the object

• Momentum of the object

• Motion of the object

• Magnitude of the object

Answer explanation

In the kinetic energy formula (KE = 1/2 mv²), 'm' represents the mass of the object. This is crucial as kinetic energy depends directly on the mass and the square of its velocity.

In the formula for gravitational potential energy, what does 'h' stand for?

• Height of the object

• Heat of the object

• Humidity around the object

• Hardness of the object

Answer explanation

In the formula for gravitational potential energy, 'h' represents the height of the object above a reference point. This height is crucial as it determines the potential energy due to gravity.

What is the approximate value of acceleration due to gravity used in the potential energy formula?

• 9.81 m/s^2

• 8.91 m/s^2

• 10.81 m/s^2

• 7.81 m/s^2

Answer explanation

The acceleration due to gravity is approximately 9.81 m/s² on Earth. This value is commonly used in the potential energy formula, making it the correct choice among the options provided.

What is thermal energy?

• Energy from the bonds of chemical compounds

• Energy from the movement of electrons

• Energy from the temperature of matter

• Energy from nuclear reactions

Answer explanation

Thermal energy is the energy associated with the temperature of matter. It arises from the kinetic energy of particles in a substance, making 'Energy from the temperature of matter' the correct choice.

Which process does not require a medium for thermal energy transfer?

• Conduction

• Convection

• Radiation

• Evaporation

Answer explanation

Radiation is the only process that transfers thermal energy without requiring a medium, as it can occur through the vacuum of space. In contrast, conduction and convection need a material medium to transfer heat.

What type of energy is stored in the bonds of chemical compounds?

• Thermal energy

• Chemical energy

• Electrical energy

• Nuclear energy

Answer explanation

Chemical energy is the energy stored in the bonds of chemical compounds. When these bonds are broken or formed during a chemical reaction, this energy is released or absorbed, making chemical energy the correct choice.

What is Ohm's Law?

• V = IR

• E = mc²

• F = ma

• P = IV

Answer explanation

Ohm's Law states that the voltage (V) across a conductor is directly proportional to the current (I) flowing through it, with resistance (R) as the constant of proportionality. Thus, the correct formula is V = IR.

What happens during nuclear fission?

• Atoms combine to form a larger nucleus

• Electrons move through a conductor

• The nucleus of an atom splits into smaller parts

• Particles move faster, increasing temperature

Answer explanation

During nuclear fission, the nucleus of an atom splits into smaller parts, releasing a significant amount of energy. This process is fundamental in nuclear reactors and atomic bombs, distinguishing it from other processes like fusion.