Which statement best describes the purpose of the vacuum inside a thermos? A. It prevents particles from transferring thermal energy between the inner and outer bottles.
B. It increases heat loss through conduction between the outer and inner bottles.
C. It prevents heat loss through radiation, which requires matter to transfer energy.
D. It allows for more collisions between the particles that make up the outer and inner bottles.

The speed of light can be used to measure the

How much energy must a refrigerator absorb from 225 g of water so that the temperature of the water will drop from 35°c to 5°c

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants