The acceleration of a particle is defined by the relation a=0.4(1-kv),...
Answer:
Given:
a = 0.4(1-kv)
At t=0, u=0, x=4m
At t=15s, v=4m/s
(a) Determine the constant k:
a = 0.4(1-kv)
At t=0, u=0, x=4m
a = 0.4(1-k(0))
a = 0.4
At t=15s, v=4m/s
a = 0.4(1-kv)
0.4 = 0.4(1-k(4))
0.4 = 0.4(1-4k)
1-4k = 1
-4k = 0
k = 0
Therefore, k = 0.
(b) The position of the particle when v=6m/s:
We need to find the position x when v=6m/s.
Given, a = 0.4(1-kv)
At t=0, u=0, x=4m
Let's integrate the expression to find the velocity function:
a = dv/dt
0.4(1-kv) = dv/dt
0.4dt = dv/(1-kv)
∫0 to t 0.4dt = ∫0 to v dv/(1-kv)
0.4t = (-1/k)ln(1-kv) + C
At t=0, u=0, x=4m
0 = (-1/k)ln(1-k(0)) + C
C = 0
0.4t = (-1/k)ln(1-kv)
When v=6m/s,
0.4t = (-1/k)ln(1-k(6))
0.4t = (-1/0)ln(1)
t = 0
We got t=0, which means the particle hasn't moved when v=6m/s. Therefore, the position of the particle when v=6m/s is 4m.
(c) The maximum velocity of the particle:
The maximum velocity occurs when the acceleration is zero, i.e., when a=0.
Given, a = 0.4(1-kv)
0 = 0.4(1-kv)
1-kv = 0
v = 1/k
Substituting k=0, we get v=∞.
Therefore, the maximum velocity of the particle is infinity.
The acceleration of a particle is defined by the relation a=0.4(1-kv),...
Since, a=dv/dt integrate the given relation with respect to time and apply the boundary conditions to get the value of "k".
Since, a=vdv/dx integrate the the relation with respect to displacement and apply the boundary conditions to get the value of "x"
for maximum velocity a=0 and find the Vmax from the original given equation.
To make sure you are not studying endlessly, EduRev has designed Civil Engineering (CE) study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Civil Engineering (CE).