In a block-spring system m = 0.25kg

and

k = 4N /m

. At

t = 0.15s

, the velocity is

v = −0.174m/s

and

the acceleration

2

a = +0.877m /s

. Write an expression for the displacement as a function of time,

x(t)

Awind turbine is rotating counterclockwise at 0.5 rev/s and slows to a stop in 10 s. its blades are 20 m in length. (a) what is the angular acceleration of the turbine? (b) what is the centripetal acceleration of the tip of the blades at t=0s? (c) what is the magnitude and direction of the total linear acceleration of the tip of the blades at t=0s?

He latent heat of vaporization for ethyl alcohol is 854 j/g. the amount of energy, rounded to the nearest whole number, needed to change 5.20 grams of ethyl alcohol from a liquid to a gas is

Anumber of conditions are required for a population to be in hardy-weinberg equilibrium. which of the following are correct descriptions of the conditions that must be met? check all that apply. a. no mutations b. random mating c. small population d. migration or gene flow e. occurrence of mutations f. no natural selection