Steep safety ramps are built beside mountain highways to enable vehicles with defective brakes to stop safely. A truck enters a
1 answer:
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Answer:
I = 4.75 A
Explanation:
To find the current in the wire you use the following relation:
(1)
E: electric field E(t)=0.0004t2−0.0001t+0.0004
ρ: resistivity of the material = 2.75×10−8 ohm-meters
J: current density
The current density is also given by:
(2)
I: current
A: cross area of the wire = π(d/2)^2
d: diameter of the wire = 0.205 cm = 0.00205 m
You replace the equation (2) into the equation (1), and you solve for the current I:
Next, you replace for all variables:
hence, the current in the wire is 4.75A
Answer:
Rod 1 has greater initial angular acceleration; The initial angular acceleration for rod 1 is greater than for rod 2.
Explanation:
For the rod 1 the angular acceleration is
Similarly, for rod 2
Now, the moment of inertia for rod 1 is
,
and the torque acting on it is (about the center of mass)
therefore, the angular acceleration of rod 1 is
Now, for rod 2 the moment of inertia is
and the torque acting is (about the center of mass)
therefore, the angular acceleration is
We see here that
therefore
In other words , the initial angular acceleration for rod 1 is greater than for rod 2.