Sam did 480 j of work when moving a bag with a mass of 38 kg. he did the work in 4 minutes. what was the power output?

a.442 w
b.20 w
c.120 w
d.2 w

Option D is the correct answer.

Step-by-step explanation:

We have expression for power,

Work done, W = 480 J

Time taken, t = 4 minutes = 4 x 60 = 240 seconds.

Option D is the correct answer.

The time time for the Acorn to descends from 13 feet to  1 feet is 52.25 seconds

Step-by-step explanation:

Given as :

The initial height of acorn = 13 feet in air

The rate of its descends = r = 4.8 feet every seconds

The final height of acorn = 1 feet

Le the time period of its descends = t sec

According to question

final height of acorn after t sec= initial height of acorn ×

Or, 1 feet = 13 feet ×

Or, 1 feet = 13 feet ×

Or, =

Or, 0.07693 =

Taking log both side

Log 0.07693 = Log ( )

or, - 1.113 = t Log (0.952)       ( from log property )

Or,  - 1.113 = t ( - 0.0213 )

∴  t =

I.e t = 52.25 sec

So , The descending time is t = 52.25 seconds

Hence The time time for the Acorn to descends from 13 feet to  1 feet is 52.25 seconds  Answer