-
Water flows though a pipe with a velocity given by V→ = 4 + x + y ĵ m/s t
m/s, where ĵ is the unit vector in the y direction, t(>0) is in seconds, and x and y are in meters. The magnitude of total acceleration at the point (x, y) = (1, 1) at t = 2 s is _____ m/s².
-
- 3 m/s²
- 29 m/s²
- 10 m/s²
- 30 m/s²
Correct Option: A
Given:
V = | + x + y | ĵ m/s | |||
t |
V = uî + vĵ + wk̂
u = 0, w = 0
V = | + x + y | ĵ | |||
t |
a = axî + ayĵ + azk̂
ax = u | + v | + w | + | = 0 | ||||
∂x | ∂y | ∂z | ∂t |
az = u | + v | + w | + | ||||
∂x | ∂y | ∂z | ∂t |
ay = u | + v | + w | + | ||||
∂x | ∂y | ∂z | ∂t |
= u | + v | ||
∂y | ∂t |
= | + x + y | × 1 + | ||||||
t | t² |
ay = | + x + y − | ĵ | ||||
t | t² |
Now, At (x,y) = 1,1 and t = 2 sec.
Total acceleration is given by,
a = ay = | + 1 + 1 − | = 3 m/s² | ||||
2 | 4 |