Answer:
Length of copper wire, l = 785 meters
Explanation:
Given that,
Resistance of the copper wire, R = 0.172 ohms
Area of cross section, 
Resistivity of copper, 
The resistance of a wire is given by :



l = 785 meters
So, the length of the copper wire is 785 meters. Hence, this is the required solution.
Answer:34 cm
Explanation:
Given
mass of meter stick m=80 gm
stick is balanced when support is placed at 51 cm mark
Let us take 5 gm tack is placed at x cm on meter stick so that balancing occurs at x=50 cm mark
balancing torque






If we assume also that the temperature of the air does not change, we can use Boyle's Law:
p₁V₁ = p₂V₂
Now, we know:
p₁ = 100kPa
V₂ = 100cm³ (the volume of the tyre)
V₁ = 120cm³ (becuse the air is contained inside the tyre AND the pump)
We can solve for p₂:
p₂ = (p₁V₁)/V₂
= (100×120)/100
= 120kPa
Therefore your answer is: 120kPa
The equation for Hall voltage Vh is:
Vh=v*B*w, where v is the velocity of the strip, B is the magnitude of the magnetic field, and w is the width of the strip.
v=25 cm/s = 0.25 m/s
B=5.6 T
w= 1.2 mm = 0.0012 m
We input the numbers into the equation and get:
Vh= 0.25*5.6*0.0012 = 0.00168 V
The maximum Hall voltage is Vh= 0.00168 V.
Complete Question
In an action movie, the villain is rescued from the ocean by grabbing onto the ladder hanging from a helicopter. He is so intent on gripping the ladder that he lets go of his briefcase of counterfeit money when he is 130 m above the water. If the briefcase hits the water 6.0 s later, what was the speed at which the helicopter was ascending?
Answer:
The speed of the helicopter is 
Explanation:
From the question we are told that
The height at which he let go of the brief case is h = 130 m
The time taken before the the brief case hits the water is t = 6 s
Generally the initial speed of the briefcase (Which also the speed of the helicopter )before the man let go of it is mathematically evaluated using kinematic equation as
Here s is the distance covered by the bag at sea level which is zero
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