Ariver has a steady speed of vs. a student swims upstream a distance d and back to the starting point. (a) if the student can swim at a speed of v in still water, how much time tup does it take the student to swim upstream a distance d? express the answer in terms of d, v, and vs. tup = incorrect: your answer is incorrect. (b) using the same variables, how much time tdown does it takes to swim back downstream to the starting point? tdown = incorrect: your answer is incorrect. your answer cannot be understood or graded. more information

Wo audio speakers are placed on a vertical rail. speaker a is placed at head-level while speaker b is place at some variable height, \delta yδy, above speaker a. both speakers receive simultaneous input from a sine-wave generator so the speakers each produce a pure sinusoidal sound wave with a wavelength of 0.531 meters. calculate the lowest height that speaker b can be placed above speaker a to produce a minimum of sound heard by person standing \delta x = 7.86δx=7.86 meters directly in front of speaker a.

According to newton's second law, when the same force is applied to two objects of different masses, a the object with greater mass will experience a great acceleration, and the object with less mass will experience an even greater acceleration, b. the object with greater mass will experience a smaller acceleration, and the object with less mass will experience a greater acceleration, c. the object with greater mass will experience a greater acceleration, and the object with less mass will experience a smaller acceleration, d. the object with greater mass will experience a small acceleration, and the object with less mass will experience an even smaller acceleration.

Lin yao looks at the back of a spoon. how should she describe her reflection? upside down and smaller upside down and larger right-side up and smaller right-side up and larger