How does the focal length (f) of a convex lens compare with the focal length
of a concave lens?

A. Both are negative.
B. The focal length of the convex lens is positive, and that of the
concave lens is negative.
C. The focal length of the convex lens is negative, and that of the
concave lens is positive.
D. Both are positive.

Which statement correctly describes the current in a circuit that is made up of any two resistors connected in parallel with a battery? a. the current in the battery and in each resistor is the same b. the current the battery equals to the sum of the currents in the resistors c.the current in the battery is less than the current in either resistor d. the current in the battery equals to the product of the currents in the resistors

Adiagram show how a converging lens can produce a real image and virtual image

A1.0 kg block is placed on top of a 2.0 kg block. a horizontal rope pulls the 2.0 kg block across a frictionless floor with a force of 21.0 n. the coefficient between the two blocks is 0.75. does the 1.0 kg block on top slide?