Physical Science Unit 5 Review

Explanation
The work done can be calculated by multiplying the force applied by the distance moved in the direction of the force. In this case, the force is 250N and the distance moved is 2.0m. Therefore, the work done is 250N * 2.0m = 500J.

Explanation
The speed of a wave is determined by the product of its wavelength and frequency. Since the speed is constant, if the wavelength increases, the frequency must decrease to maintain the same speed, and vice versa. This inverse relationship between wavelength and frequency is a fundamental property of waves, known as the wave equation. Therefore, the statement that wavelength and frequency have an inverse relationship when the speed of a wave is the same is true.

Explanation
Boyle's Law states that there is an inverse relationship between the pressure and volume of a gas. This means that as the pressure increases, the volume decreases, and vice versa. This relationship is explained by the fact that when the volume of a gas decreases, the gas particles are forced closer together, resulting in more frequent collisions with the container walls and thus an increase in pressure. Conversely, when the volume increases, the gas particles have more space to move around, resulting in fewer collisions and a decrease in pressure.

Explanation
The energy of a rolling ball can be calculated using the formula for kinetic energy, which is given by KE = 0.5 * m * v^2, where m is the mass of the ball and v is its velocity. In this case, the mass of the ball is given as 1.50kg and the velocity is given as 3.00m/s. Plugging these values into the formula, we get KE = 0.5 * 1.50kg * (3.00m/s)^2 = 6.75J. Therefore, the correct answer is 6.75J.

Explanation
Aluminum has a high specific heat capacity compared to the other materials listed. Specific heat capacity is the amount of heat energy required to raise the temperature of a substance by a certain amount. Since aluminum has a higher specific heat capacity, it would require more heat energy to raise its temperature from 20.0°C to 100.0°C compared to the other materials. Therefore, 50g of aluminum would take the longest to heat in the same fire.

Explanation
Temperature and heat are not measured with the same units. Temperature is measured in degrees Celsius, Fahrenheit, or Kelvin, while heat is measured in units of energy, such as joules or calories. Temperature is a measure of the average kinetic energy of the particles in a substance, while heat is the transfer of energy between two objects due to a temperature difference. Therefore, the given statement is false.

Explanation
Joules and Calories are both units of measurement for energy. Joules is the standard unit of energy in the International System of Units (SI), while Calories is a unit commonly used in nutrition to measure the energy content of food. Newtons, on the other hand, measure force, not energy. Hz (hertz) is a unit of frequency, not energy. Therefore, the correct units for measuring energy in this question are Joules and Calories.

Explanation
Temperature is the measurement of the total kinetic energy of the particles that make up matter. It represents the average kinetic energy of the particles in a substance. When the particles move faster, they have higher kinetic energy and the temperature increases. Conversely, when the particles move slower, they have lower kinetic energy and the temperature decreases. Therefore, temperature is a measure of the thermal energy or heat present in a substance.

Explanation
This statement is false because even though an object at rest may not possess kinetic energy (energy of motion), it can still have potential energy (stored energy) due to its position or condition. Additionally, objects at rest can also have other forms of energy such as thermal energy or chemical energy. Therefore, it is incorrect to say that an object at rest cannot have energy.

Explanation
The statement "Light moves at a speed of 340m/s" is false. The speed of light in a vacuum is approximately 299,792 kilometers per second, or about 186,282 miles per second. It is important to note that the speed of light can vary depending on the medium it is traveling through, such as air or water, but in a vacuum, it is approximately 299,792 kilometers per second.