1.
What is energy?
Correct Answer
C. To be able to do work
Explanation
Energy is the ability or capacity to do work. It is the power or agility to perform tasks and accomplish goals. Energy is required to push and pull objects, complete tasks, and carry out any form of work. It is the underlying force that enables actions and movements to occur.
2.
The S.I. unit of energy is?
Correct Answer
B. Joule
Explanation
The SI unit of energy is the joule. The joule is defined as the amount of energy transferred when a force of one newton is applied over a distance of one meter. It is commonly used to measure various forms of energy such as mechanical, thermal, and electrical energy. The watt is the SI unit of power, not energy. The newton is the SI unit of force, and the kilogram is the SI unit of mass.
3.
Which of the following is NOT a type of energy?
Correct Answer
B. Fuel
Explanation
Fuel is not a type of energy, but rather a substance that can be burned or consumed to produce energy. Energy can be derived from various sources such as thermal, nuclear, or strain, but fuel itself is not considered a type of energy. It is a material that can be converted into energy through various processes.
4.
Which of the following groups of energy is described as 'energy of movement'?
Correct Answer
A. Thermal and electrical
Explanation
Thermal and electrical energy can both be described as "energy of movement" because they involve the movement of particles or charges. Thermal energy is the energy associated with the movement of atoms and molecules, while electrical energy is the energy associated with the movement of electrons. Both forms of energy involve the transfer or conversion of kinetic energy, making them appropriate choices for the description of "energy of movement".
5.
Which type of energy is found in food?
Correct Answer
D. Chemical
Explanation
Food contains chemical energy. This is because food is made up of molecules that can be broken down through chemical reactions to release energy. When we eat food, our bodies break down the molecules in the food through digestion, and this releases the stored chemical energy, which our bodies then use for various functions such as movement, growth, and maintaining body temperature.
6.
Which of the following type of energy is NOT a stage in the energy transformation of a Flashlight?
Correct Answer
B. Mechanical
Explanation
Mechanical energy is not a stage in the energy transformation of a flashlight. A flashlight works by converting chemical energy from the batteries into electrical energy, which then gets transformed into light energy. Mechanical energy, which refers to the energy associated with the motion or position of an object, is not involved in this process.
7.
What is gravitational potential energy?
Correct Answer
B. Energy above a leveled surface
Explanation
Gravitational potential energy refers to the energy that an object possesses due to its position above a leveled surface. It is the energy that an object has when it is raised above the ground level. This energy is a result of the gravitational force acting on the object, and it can be converted into other forms of energy when the object falls or moves downward.
8.
Which of the following quantities do we NOT need to calculate potential energy?
Correct Answer
C. Weight
Explanation
Weight is not needed to calculate potential energy because potential energy is determined by the height of an object and its mass, not its weight. Weight is a force that is dependent on the mass of an object and the acceleration due to gravity, but it is not directly used in the calculation of potential energy. Therefore, weight is not necessary to calculate potential energy.
9.
What is the height above ground of a roller coaster that has a potential energy of 32.4 J and a mass of 34000 grams?
Correct Answer
C. 0.097 m
Explanation
The potential energy of an object is given by the formula PE = mgh, where m is the mass, g is the acceleration due to gravity, and h is the height above ground. Rearranging the formula, we can solve for h: h = PE / (mg). Plugging in the values given, we get h = 32.4 J / (34000 g * 9.8 m/s^2). Converting grams to kilograms, we have h = 32.4 J / (34 kg * 9.8 m/s^2) = 0.097 m. Therefore, the height above ground is 0.097 m.
10.
Which of the following is a renewable source of energy?
Correct Answer
C. Solar energy
Explanation
Renewable energy sources are those that can be replenished naturally over a relatively short period. Solar energy, derived from the sun's radiation, is a renewable source as it is constantly being replenished. The other options are non-renewable sources, as they are finite and take millions of years to form.
11.
Which scientist stated the law of conservation of energy?
Correct Answer
C. Albert Einstein
Explanation
Albert Einstein is the correct answer because he formulated the theory of relativity, which includes the principle of the conservation of energy. This principle states that energy cannot be created or destroyed, but only transformed from one form to another. Einstein's theory revolutionized our understanding of energy and its relationship to mass, leading to the famous equation E=mc^2, which shows the equivalence of energy and mass. Therefore, Einstein's contributions to physics solidified the concept of the conservation of energy.
12.
Which of the following options does NOT agree with the law of conservation of energy?
Correct Answer
D. Energy can be created in another form
Explanation
The law of conservation of energy states that energy cannot be created or destroyed, but only transformed from one form to another. This means that the total amount of energy in a closed system remains constant. The option "Energy can be created in another form" contradicts this law, as it suggests that energy can be created, which goes against the principle of conservation.