When an electric current is flowing through a wire, there is a magnetic <em>field</em> produced. The lines of magnetic force are circles around the wire.
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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Answer: its mechanical energy
Explanation:
Answer:
(d) III only
Explanation:
We have to observe the motion of the bag with respect to taxi , considering taxi as stationary or inertial frame . Since bag is not moving with respect to taxi , the inertial frame that means , net force on it is zero .So option i and ii are ruled out .
Now how to explain motion of the bag ie why it is stationary ie what are the balancing force acting on it. We know that on a body on circular path , a force called centripetal force is acting on it . So that force must be acting on it . The balancing force is the frictional force which is keeping it stationary with respect to taxi . Hence the third option is correct.
Answer:
A. The energy is not truly lost: it transforms into forms that are not easily put to use.
Explanation:
This is due to the fact that when we use energy, it seems to have disappear, but it really hasn't. In fact, when we use energy, it is changing into another form that has to be converted in order for energy to be present once again.
