Pls help me with this Proba-1 satellite orbits the Earth at a height of 700km. What is the linear speed of this satellite?

[G=6.67×10^-¹¹ N m² kg^-²]
[mass of the Earth=5.97× 10^²⁴]
[radius of the Earth= 6.37 × 10^⁶ m]​

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".