Example 1: Two physics students, Ben and Bonnie, are in the weightlifting room. Bonnie lifts the 50kg barbell over her head (approximately .60 m) 10 times in one minute; Ben lifts the 50 kg barbell the same distance over his
head 10 times in 10 seconds.
o Which student does the most work?
O
Which student delivers the most power?

Same

Ben.

Explanation:

m = Mass Bonnie and Ben lift = 50 kg

s = Displacement of mass by both the students = 0.6 m

Work done by both the student is

The amount of work done by both the students will be equal to 300 J.

= Time taken by Bonnie = 1 minute = 60 seconds

= Time taken by Ben = 10 seconds.

Power delivered by Bonnie

Power delivered by Ben

So, power delivered by Ben is more.

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.