Answer:
it's is because the heavier the object is the more it will be pulled down by gravity n the lighter the object the lesser the gravity will pull it down
We are given that the maximum mass capacity is 1 metric
ton or 1000 kg. Therefore the amount of people this can hold is simply the
ratio of the maximum mass capacity over the mass of the person, that is:
people = 1000 kg / 91 kg
people = 10.98
So the elevator can safely occupy 10 people. We will not exceed to 11.
1250 J in 5 sec= 250 Joule(s) per second (1250/5 0
250 Joules per second = 250 Watts ( 1J/s = 1 Watt per definition)
250 Watts output = 250/0.65 efficiency = 384 Watts input
1 Horsepower = 732 Watts
Motors 1 Horsepower and under are made in certain step sizes like
3/4 , 1/2 , 1/3, 1/4, 1/16 1/20 of a Horsepower.
3/4 Horsepower is 549 Watts
1/2 Horsepower is 366 Watts
so you need to 3/4 horsepower motor to achieve 1250 J of work in 5 seconds.
I believe the answer is D
Stairs don't have any power at all. All the energy used to climb them
has to come from your muscles.
An elevator gets its power from the electric motors that lift it. All YOU
have to do is stand there and look around.
All of this is a big part of the reason why elevators have become so
popular, and why no buildings with more than a few floors were built
before elevators were invented.