Hello help me please The following parametric equations are :

x(t) = 2cosπt
y(t) = 2sinπt
z(t) = 0
Determine:

1) the modulus of the velocity vector at the instant t.
2) the modulus of the acceleration vector at any time "t'
3) The equation of the mobile and its trajectory.

Achemistry student needs of 40ml diethylamine for an experiment. by consulting the crc handbook of chemistry and physics, the student discovers that the density of diethylamine is 0.7 . calculate the mass of diethylamine the student should weigh out. round your answer to significant digits.

Organelles are 1. responsible for producing power for the cell 2. tiny structures in the cell that carry out the cell's activities 3. responsible for digestion in the cell 4. found outside of the membrane

One object has a mass of 1 kg and another object has a mass of 3 kg. if the speeds are the same, which of the following is true about their kinetic energy?