Answer:
2.66m/s
Explanation:
information we have
power: 65W
work per step per kilogram: 0.60J
mass: 61kg
length of a running step: 1.5m
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the formula for power is:
where W is the work and t is time.
time is also defined as: 
so substituting this into the formula for power we get:
where v is the velocity we are looking for, d is the distance per step: 
, W is the work per step and P is power 
.
we know that the work per step per kilogram is:
0.60J
so to find the work per step of his whole body we need to multiply the 0.60J by the 61 kilograms of his mas:
this is the work per step of the person.
So now we can calculate the velocity using the formula for power
clearing for v:
and substituting known values:
Velocity =
(displacement)/(time for the displacement), in the direction of the displacement.
Displacement = 8 m south
Time for the displacement = 4 seconds
Direction of the displacement = south
Velocity (8 m south) / (4 seconds), to the south
Velocity = 2 m/s, toward the south
Answer:
The average speed will be 1.5km/hr .
Explanation:
Distance need to be traveled = 7.5Km
Time taken = 5 hours
Average speed refers to total distance traveled with respect to total time taken .
It can be calculated as given below :
Average speed =total distance /total time taken
Substituting the values we get ,as shown below
Average speed =7.5/5=75/50
Average speed = 1.5 Km/hr
Electromagnetic transverse waves
Edit
In physics, power is the rate of doing work or of transferring heat, i.e. the amount of energy transferred or converted per unit time. Having no direction, it is a scalarquantity. In the International System of Units, the unit of power is the joule per second (J/s), known as the watt in honour of James Watt, the eighteenth-century developer of the condenser steam engine. Another common and traditional measure is horsepower (comparing to the power of a horse). Being the rate of work, the equation for power can be written:
Power
Common symbols
Derivations from
other quantities
P = E/t
P = F·v
P = V·I
P = T·ω
As a physical concept, power requires both a change in the physical system and a specified time in which the change occurs. This is distinct from the concept of work, which is only measured in terms of a net change in the state of the physical system. The same amount of work is done when carrying a load up a flight of stairs whether the person carrying it walks or runs, but more power is needed for running because the work is done in a shorter amount of time.
