Aparticle of mass 4.0 kg is constrained to move along the x-axis under a single force f(x) = −cx3 , where c = 8.0 n/m3 . the particle’s speed at a, where xa = 1.0 m, is 6.0 m/s. what is its speed at b, where xb = −2.0 m?

Apossible explanation for a set of facts that can be tested by further investigation is called

1kg of water needs to recieve 4200j of energy to go from 90 degrees to 91 degrees. what is the specific heat capacity of water? what are the units?

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".