Which of the following is true for a system consisting of a mass oscillating on the end of an ideal spring?

a. the kinetic and potential energies are equal at all times.
b. the kinetic and potential energies are both constant.
c. the maximum potential energy is achieved when the mass passes through its equilibrium position.
d. the maximum kinetic energy and maximum potential energy are equal, but occur at different times.
e. the maximum kinetic energy occurs at maximum displacement of the mass from its equilibrium position.

An architect plans to use solar energy to heat the next house he designs. what principle of absorption and infrared energy can be applied to the design of the new house? how could she apply to those principals?

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

Place several e-field sensors at a few points on different equipotential lines, and look at the relationship between the electric field and the equipotential lines. which statement is true? 1-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of higher voltages. 2-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of lower voltages. 3-at any point, the electric field is parallel to the equipotential line at that point.