Suppose that you'd like to find out if a distant star is moving relative to the earth. The star is much too far away to detect any change in its brightness as it moves toward or away from the earth. Instead we can use the Doppler effect to determine its relative speed. For this problem we are going to look at the spectral lines from hydrogen, specifically the one with a wavelength of 656.46 nm. Suppose that you measure the light of a star between 640 and 680 nm and you get a very strong peak around 650 nm. What can you say about the star's motion? Please provide a detailed explanation.

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".

Debris produced by mining is called

Consider motion in one dimension. (the sign of the vector quantities is their direction indicator.) an object moves in the positive x-direction with speed 2.9 m/s for 4.5 s. it stops for 3.8 s and then moves in the negative x direction with speed 2.8 m/s for 4 s. what is the total distance traveled by the object in units of meter? enter a number with two digits behind the decimal point.