Standard deviations can be compared Multiple select question. only for data sets with the same measurement units. for data sets with the same measurement units but greatly different magnitudes. only for data sets with the same measurement units and similar magnitude. for data sets with different measurement units.

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.