Answer:
Explanation:
height of pole = 15 ft
height of man = 6 ft
Let the length of shadow is y .
According to the diagram
Let at any time the distance of man is x.
The two triangles are similar

15 y - 15 x = 6 y
9 y = 15 x

Differentiate with respect to time.

As given, dx/dt = 4 ft/s

ft/s
THE MINI
Alec Issigonis, 1959
The Telephone
Alexander Graham Bell, 1876
http://www.radiotimes.com/news/2013-01-08/the-50-greatest-british-inventions
Answer:1.04 N
Explanation:
Given
Gravitational Force on the Platter is 
Tray makes an angle of 
This gravitational Force has components along and Perpendicular to Platter
Perpendicular Force 

Along the Tray


Thus 1.04 N is the magnitude of force that will cause Platter to slide down
The answer is 0.025J.
W=1/2*k*x^2
W=1/2*20*0.050^2
W=0.025J