(4.) The magnitude of the vector sum of two vectors a and b is 8u, and magnitude of b is 5u. If the direction of a is reversed, the magnitude of the vector sum becomes 10u. Find the angle between a and b

Apiano tuner uses a tuner to create a tone of 5.00 x 10² hz. when a key on the piano is struck he hears 5 beats per second. what is a possible frequency of vibration for the piano string? 2500 hz 1300 hz 605 hz 495 hz

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is