Can anyone just check my answers and tell me if correct or not. if i’m incorrect, tell me the correct on a windless day, train a is traveling down a grade at 50 m/s and passes train b, which is moving up the grade at half that speed. after the trains pass, train a blows it’s 300 hz whistle. what frequency is heard by a passenger on train b. 312 hz 435 hz 243 hz(my choice) 186 hz a police officer parked at the curb turns on his lights and siren, waits for traffic to clear, then pulls out and heads down the street. for an observer down the street, which is true? the frequency of the siren is higher and the wavelength is shorter than it was at first. the wavelength of the siren is shorter than it was at first, but the frequency is the same(my choice) the wavelength of the siren is shorter and the frequency is lower than it was at first. the frequency of the siren is higher than it was at first, but the wavelength is the same

When the velocity of an object is doubled, by what factor is its momentum changed? by what factor is its kinetic energy changed? a) the momentum is zero. b) the momentum is not zero. c) difficult to say.

Increasing the pressure on one spot of a fluid will increase the pressure everywhere else in the fluid a. pascals principal b. archimedes' principal c. bernoulli's principal

An charge with mass m and charge q is emitted from the origin, (x,y)=(0,0). a large, flat screen is located at x=l. there is a target on the screen at y position y(h), where y(h) > 0. in this problem, you will examine two different ways that the charge might hit the target. ignore gravity in this problem. 1.assume that the charge is emitted with velocity v(0) in the positive x direction. between the origin and the screen, the charge travels through a constant electric field pointing in the positive y direction. what should the magnitude e of the electric field be if the charge is to hit the target on the screen? express your answer in terms of m, q, y(h), v(0), and l. 2.now assume that the charge is emitted with velocity v(0) in the positive y direction. between the origin and the screen, the charge travels through a constant electric field pointing in the positive x direction. what should the magnitude e of the electric field be if the charge is to hit the target on the screen? express your answer in terms of m, q, y(h), v(0), and l.