Aparticle is moving along the x-axis so that its position at any time t is greater than and equal to 0 is given by x(t)=2te^-t?
a) find v(t).
b) find a(t).
c) at t=0, is the particle slowing down or speeding up? explain.
d) at what time(s), if any, does the particle change directions? justify your answer.
any would be greatly appreciated! !

The human body stores chemical energy from digested food. some of the chemical energy is converted into mechanical energy when the body moves. which statement best supported by this information

While carrying a heavy box up the stairs, you set the box on a step and rest. then you pick up the box and carry it to the top of the stairs. describe these actions in terms of balanced and unbalanced forces acting on the box.

The amount of heat required to change liquid water to vapor at its boiling temperature is 2256 kj/kg. the amount of heat required to change liquid mercury to its vapor state at its boiling temperature is 295 kj/kg. one kg of each substance is currently at its boiling point. how will the amount of thermal energy required to change each substance from a liquid to a gas differ?