Which sounds can be heard safely by humans without
risking damage to the ear? Check all that apply.
O
rustling leaves
normal conversation
vacuum cleaner
front row at a rock concert
jet takeoff

These sounds can be heard safely by humans without risking permanent hearing loss:

-- rustling leaves . . . . . Yes

-- normal conversation  . . . . . Yes

-- vacuum cleaner  . . . . . Yes IF it's on the floor and you're standing up.

-- front row at a rock concert . . . . . No

-- jet takeoff . . . . . Yes BUT only if you're at least a mile away from the jet.

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.

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.