People fighting forest fires carry emergency tents that haveshiny aluminum outer surfaces. if there is trouble, a fire fightercan lie under the tent to block the heat from burning treesoverhead. the tent because
a) radiation carries heat downward toward the fire fighter and thealuminum tent reflects most of that radiation.
b) convection carries heat downward toward the fire fighter and thealuminum tent blocks most of the heat carried by convection.
c) both conduction and radiation carry heat downward toward thefire fighter and the aluminum tent blocks most of that heat.
d) conduction carries heat downward toward the fire fighter and thealuminum tent conducts that heat harmlessly into the ground.

The best answer i can think of is b

The figure is missing but we can answer anyway.the correct answer is "releasing the string". in fact, when the person is holding the bow and the arrow, the kinetic energy of the arrow is still zero (because the arrow is not moving). the moment the arrow is released, it acquires a velocity v, so its kinetic energy will become different from zero: where m is the mass of the arrow and v its velocity.  all the other options, instead, do not increase the kinetic energy of the system: -  pulling farther back on the string : this will just increase the elastic potential energy of the system-  holding the arrow higher: this will increase the gravitational potential energy of the system (which is given by u=mgh, where h is the height above the ground)-  decreasing the mass of the arrow: this will decrease the gravitational potential energy of the system (which is given by u=mgh, where m is the mass)