a horizontal and vertical force acts on a body . the horizontal force is fixed at 4N but the vertical force varies. calculate the magnitude of the vertical force if the magnitude of the resultant is 6N​

An electromagnetic wave with frequency 65.0 hz travels in aninsulating magnetic material that has dielectric constant 3.64 andrelative permeability 5.18 at this frequency. the electric fieldhas amplitude 7.20 \times 10^{ - 3} {\rm v}/{\rm m}. a. what is the speed of propagation of the wave? b. what is the wavelength of the wave? c. what is the amplitude of the magnetic field? d. what is the intensity of the wave?

What do we mean by the event horizon of a black hole?

1,990,000,000,000,000,000,000,000,0 00,000 in scientific notation