A child appears to be running into the street ahead. It takes 2.3 seconds for the driver to react and begin to brake, but this time at a rate of -7.5 m/s2. What is the stopping distance for the car in this situation?

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up

How can waves travel through ground?

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?