Question

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?

Answer 1

Same

Ben.

Step-by-step 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

`W=Fs\\\Rightarrow W=10* 50* 0.6\\\Rightarrow W=300\ \text{J}`

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

`t_1` = Time taken by Bonnie = 1 minute = 60 seconds

`t_2` = Time taken by Ben = 10 seconds.

Power delivered by Bonnie

`P=(W)/(t_1)\\\Rightarrow P=(300)/(60)\\\Rightarrow P=5\ \text{W}`

Power delivered by Ben

`P=(W)/(t_2)\\\Rightarrow P=(300)/(10)\\\Rightarrow P=30\ \text{W}`

So, power delivered by Ben is more.