Mary starts from her house, walks 80 meters south, and stops to chat with her aunt on the sidewalk. after chatting for a few minutes, she walks 125 meters to the west to meet a friend and then walks 45 meters north with her friend to a cafe for lunch. overall, she takes 10 minutes to do all this. what is mary’s average speed?

Total distance (in metres)= 80+125+45=250

Total time (minutes) =10

250/10

=25

Explanation:

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.