An object with mass 60 kg moved in outer space. When it was at location < 14, -2
ID: 1874119 • Letter: A
Question
An object with mass 60 kg moved in outer space. When it was at location < 14, -23, -6 > its speed was 18.5 m/s. A single constant force < 210, 500, -210 > N acted on the object while the object moved to location < 20, -28, -10 > m. What is the speed of the object at this final location?
final speed = m/s
Explanation / Answer
Given that,
m = 60 kg
location r1 = <14, -23 , -6> m
r2 = <20, -28 , -10> m
F1 = <210, 500 , -210> N
vi = 18.5 m/s
Path difference, r = r2 - r1
r = <6 , -5 , -4>
Work done by Force F,
W = F.r = (210, 500 , -210 ) . (6 , -5 , -4)
W = -400 J
lnitial energy, Ei = (1/2)mvi^2
Ei = (1/2)*60*(18.5)^2 = 10267.5 J
Final energy, Ef = 10267.5 - 400 = 9867.5 J
from energy conservation,
Ef = (1/2)mvf^2
where, vf = speed of obect at final location
9867.5 = (1/2)*60*vf^2
vf = 18.13 m/s