Answer:
The assertion is true and reason is false.
Explanation:
Assertion: I P+ Q I = I P- QI, then P must be perpendicular to Q.
Reason : The relation will hold even when Q is a null vector.
Now
So, P and Q are perpendicular to each other.
So, the assertion is true.
Reason is false.
The wind tunnel speed that must be used to test the car 1 / 5 model of a car that normally runs at 30 mph is 150 mph
Re = u L / ν
Re = Reynold's number
u = Flow speed
L = Characteristic linear dimension
ν = Kinematic viscosity
ν = 1.516 *
m² / s
ν = ν
= 1.516 *
m² / s
L = L
/ 5
u = 30 mph
Re = u
L
/ 5 * 1.516 *
Re = 30 L
/ 1.516 *
In tunnel,
Re = Re
u L
/ 5 * 1.516 *
= 30 L
/ 5 * 1.516 *
u = 30 * 5
u = 150 mph
Therefore, the wind tunnel speed that must be used to test the car is 150 mph
To know more about Reynold's number
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