Why is tycho brahe often called “the greatest naked-eye astronomer” of all time?

Akg a of 55 m at an of 11 ? . if is at 98 km/h, be ?

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".

What can change the speed of sound as it travels through the ocean? a. salinity only b. density and salinity c. salinity and distance from land d. density and distance from land