Answer:
Explanation:
-Assume the snowball is a spherically perfect:
#
Therefore, at the time of interest, we plug the value of dA/dt and r(r=6cm):
Hence, the diameter is decreasing at a rate of
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.
Hello,
<span>You are in an airplane, you look out the window and the clouds appear to be moving, your frame of reference is the window. As the frame of reference can not be accelerating, clouds accelerate, and so does the airplane.
Faith xoxo</span>
Answer:
Yes, the sun can fade the color of the rug.
Explanation: