Explanation:
This how you do it..
Calculate Watt-hours Per Day. Device Wattage (watts) x Hours Used Per Day = Watt-hours (Wh) per Day. ...
Convert Watt-Hours to Kilowatts. Device Usage (Wh) / 1000 (Wh/kWh) = Device Usage in kWh. ...
Find Your Usage Over a Month.
Answer:
Mass of bike = 38 kg.
Explanation:
Kinetic energy is given by the expression,
, where m is the mass and v is the velocity.
Here speed of child riding bike = 6 m/s
Mass of child = 30 kg
Total kinetic energy = 1224 J
Let the mass of bike be, m kg
So, total mass of child and bike = (m + 30) kg
Substituting,

So, mass of bike = 38 kg.
Answer:
Power
Explanation:
Power is defined as the rate of doing work with reference to the time spent and the formula is force multiplied by velocity.
In this case, if two people lift identical stacks of books the same distance and one person does the job twice as fast, then it means the velocity in the case is doubled which will also lead to an increase in the Power .
Answer:
A. potential energy is 258720 Joule
Explanation:
A.Gravitational potential energy is: PE = m × g × h
velocity = 15.33 m/s when the car reaches the bottom of the hill.
where, m = mass
g = acceleration due to gravity
h = height from the bottom of hill.
The potential energy is : m×g×h
=(2200×9.8×12)
=258720 Joule
B. at the bottom of the hill, the potential energy is converted into kinetic energy so PE at top = KE at bottom
kinetic energy=
(
)
where v = velocity
m= mass
therefore, v=
or, v=
or, v=15.33 m/s