True or false: Black holes are invisible because they do not reflect light? A. true B. false

A parent swings a 11.5 kg child in a circle of radius 0.711 m, making 12 revolutions in 27.4 s. How much force does the parent exert on the child? (Unit = N)

If R1 = 6 Ω, R2 = 8 Ω, R3 = 2 Ω, ε1 = 4 V, and ε2 = 14 V, what is the current in R

Four balls are taken to the top of a building. Ball 1 is dropped (zero initial velocity). Ball 2 is thrown straight up with a velocity of 3 m/s. Ball 3 is thrown straight out with a horizontal velocity of 3 m/s.

During which stage of prophase i does crossing over take place?

Heat is added to each block at the same constant rate until it reaches a temperature of 500 k. which of the following statements is true? the specific heat capacity of aluminum is about twice that of iron.

Bus A and Bus B leave school on a field trip when a stopwatch reads zero. Bus A travels at a constant 50 km/h, and Bus B travels at a constant 75 km/h. How far are the two buses from school when the stopwatch reads 1.5 h?. a ... Bus A is 76.

When observed from Earth, the wavelengths of light emitted by a star are shifted toward the red end of the electromagnetic spectrum. Why does this redshift occur?

Object A has a length of 3 cm, a width of 10 cm, and a height of 2 cm. Object B is dropped into a graduated cylinder. It displaces 60 mL of water. The volume of object A is:

Is the following sentence true or false? Some information about an object or process may be missing from a model.

If V is a velocity, l a length, and v a fluid property having dimensions of L2T-1, which of the following combinations are qualitatively dimensionless (show work for a through d) : (a) V l v (b) Vl/v (c) V2v (d) V / (l v)