Answer:
t = 12 s
Explanation:
To find the time in which the police reaches the thief you write the equation of motion of both thief and police:
The thief has a constant velocity, the position is then given by:
(1)
The police has an acceleration, then the position is:
(2)
the time in which the police reaches the thief is when their positions are equal, that is, when expression (1) equals expression (2). But before you calculate the acceleration of the police:
you replace this values in (2) and you equal the expression (1) and (2) (with vo = 0):
one root is t = 0s, but it is omitted because is the momment in which the thief pass in front of the police. The other root is:
hence, the time is 12 s
Answer:
A phenomenon!
Explanation:
That I think was observed when a Faraday cage operates to block the effects of an electric field. (RANGE SOURCE).
Answer:
a. V=11.84 m/s
b.x=0.052m
Explanation:
a).
Given
,
, 
.
b).
No friction on the ball so:
solution:
write the coordinates of the points A and B
A= (0,0,14)ft
B= (5,-6,0)ft
write the position vector of a with recpect to b
R_{BA}=(0-5)i+(0-(-6))j+(14-0)k
=-5i+6k+14k
calculation of a magnitude of the vector R_{BA}
\left | R_{BA} \right |=\sqrt{(-5)^2+6^2+14^2}
=\sqrt{25+36+196}
=16.031ft
calculation of the unit vector
\frac{-5i+6k+14k}{16.031}
calculation of the force
F_{BA}=R_{BA}U_{BA}
here, F_{BA} is the magnitude of the force.
substitute 350lb for F_{BA} and (\frac{-5i+6k+14k}{16.031}) for U_{BA}.
F_{BA} = 350 x (\frac{-5i+6k+14k}{16.031})
=-109.2i+131j+305.7k lb
