Answer:
a. 120 W
b. 28.8 N
Explanation:
To a good approximate, the only external force that does work on a cyclist moving on level ground is the force of air resistance. Suppose a cyclist is traveling at 15 km/h on level ground. Assume he is using 480 W of metabolic power.
a. Estimate the amount of power he uses for forward motion.
b. How much force must he exert to overcome the force of air resistance?
(a)
He is 25% efficient, therefore the cyclist will be expending 25% of his power to drive the bicycle forward
Power = efficiency X metabolic power
= 0.25 X 480
= 120 W
(b)
power if force times the velocity
P = Fv
convert 15 km/h to m/s
v = 15 kmph = 4.166 m/s
F = P/v
= 120/4.166
= 28.8 N
definition of terms
power is the rate at which work is done
force is that which changes a body's state of rest or uniform motion in a straight line
velocity is the change in displacement per unit time.
Answer:
in the direction of motion of Jacob
Explanation:
Given:
mass of Jacob, 
velocity of Jacob, 
mass of Ethan, 
velocity of Ethan, 
Now using the conservation of linear momentum for the case:
(When the two masses in motion combine to form one after the collision then they will move together in the direction of the greater momentum.)
in the direction of motion of Jacob as it was assumed to be positive.
Answer:
Not quite
Explanation:
The frequency of a wave is inversely proportional to its wavelength. That means that waves with a high frequency have a short wavelength, while waves with a low frequency have a longer wavelength
What determines the strength of a wave?
Wave height is affected by wind speed, wind duration (or how long the wind blows), and fetch, which is the distance over water that the wind blows in a single direction. If wind speed is slow, only small waves result, regardless of wind duration or fetch.
So,
As Wavelength increases, The energy of the wave spreads and it decreases
Answer:
number of quantum states = 8
Explanation:
To find the total number of allowed states you take into account the following relations:
in this case you have:
furthermore, for each n,l,ml quantum state you have two additional states due to the spin of the electrons.
then, you have (n,l,ml) = (2,0,0), (2,1,-1), (2,1,0), (2,1,1) and with the spin:
number of quantum states = 2*(1+3) = 8
