Question

Leo and david are always competing to see who is the strongest. in one contest, leo lifts 15 boxes, each with a mass of 30 kg, onto a shelf that is 2.3 m high in a time of 5.1 s. david lifts 18 boxes, each having a mass of 27.3 kg, onto a shelf that is 2.5 m high in a time of 5.7 s. which one produces the most power lifting all their boxes?

Answer 1

To compare the strength of the two we need to find the power deliver by each person.

If a person deliver more power then his strength will be more

Now in order to find the power we can say

`P = (work)/(time)`

in order to define work to move mass to certain height above the ground we can say it is

`W = mgh`

now we will have

Power of Leo is

`P_1 = (N_1 m_1 g h_1)/(t_1)`

`P_1 = (15* 30* 9.8*2.3)/(5.1)`

`P_1 = 1988.8 Watt`

Power of David is

`P_2 = (N_2 m_2 g h_2)/(t_2)`

`P_2 = (18* 27.3* 9.8*2.5)/(5.7)`

`P_2 = 2112.15 Watt`

So here we can say that power of David is more so David is more strong than Leo.