15 1 st Session 2002:
Mains
The graph below represents the variations,
as a function of time, of the voltage across
the terminals of a generator.
Take (V2 = 1.4).
The oscilloscope is adjusted as follows:
Horizontal sensitivity Sh
= 5 ms/ div.
Vertical sensitivity Sy
= 5 V / div.
B
А
D
С
E
F
a. Is the voltage :
• direct or alternating ?
triangular or sinusoidal ?
b. Specify a point on the graph that may be
used to determine the maximum value U
of the voltage. Calculate Um
m
m'

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

If a tank filled with water contains a block and the height of the water above point a within the block is 0.8 meter, what is the pressure at point a?

Adolphin emits ultrasound at 100khz and uses the timing of reflections to determine the position of objects in the water. part a what is the wavelength of this ultrasound? assume that temperature of water is 20 degrees c. answer in cm