Answer:
The rate of change of the shadow length of a person is 2.692 ft/s
Solution:
As per the question:
Height of a person, H = 20 ft
Height of a person, h = 7 ft
Rate = 5 ft/s
Now,
From Fig.1:
b = person's distance from the lamp post
a = shadow length
Also, from the similarity of the triangles, we can write:
Differentiating the above eqn w.r.t t:
Now, we know that:
Rate =
Thus
Energy = 1/2mv^2
Mass = 130kg
Speed = 5m/s
1/2 x 130 x 25
= 1625J
a. neutron stars
d. main sequence stars
Are smaller than the sun but I'm not sure about white dwarfs because a typical white dwarf is about as massive as the <span>Sun, yet only slightly bigger than the Earth.</span>