1 ) The motion of a particle is defined by the relation x = 2t3 - 9t2 + 12t + 10 , where x and t are expressed in feet and seconds , respectively . Determine the time , the position , and the acceleration of the particle when v = 0 ?
A ) t = 1 s , x = 15 ft
, a = 6 ft / s2 And
t = 2 s , x =
14 ft , a =
6 ft / s2 .
B ) t = 3 s , x = 15 ft
, a = 8 ft / s2 And
t = 5 s , x
= 14 ft , a =
12 ft / s2 .
C ) t = 2 s , x = 15 ft
, a = 9 ft / s2 And
t = 4 s , x =
14 ft , a = 7 ft / s2 .
Correct
Answer : - A ) t = 1 s
, x = 15 ft
, a = 6 ft / s2 And
t =
2 s , x =
14 ft , a =
6 ft / s2 .
Solution : -
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2
) During a parasailing ride , the boat is traveling at a constant 30 km / hr
with a 200 m long tow line . At the instant shown , the angle between the line and the water is 30°
and is increasing at a constant rate of 2°/s . Determine the velocity and acceleration of the
parasailer at this instant .
A ) vp = 13.280 m /
s , a = 0.2437
m / s2 .
B ) vp = 11.280 m
/ s , a = 9.2437
m / s2 .
C ) vp = 12.280 m
/ s , a = 8.2437
m / s2 .
Correct
Answer : - A ) vp =
13.280 m / s , a = 0.2437
m / s2 .
Solution : -
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