Please help ! A position versus time graph is shown below.

Use the graph to determine the instantaneous velocity in m/s of the object at 7.0 seconds?

a. 0 m/s
b. 1.4 m/s
c. 7 m/s
d. 10 m/s

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

Simple machines can a. increase force only b. decrease force only c. increase or decrease force

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)