When a potential difference of 10 V is placed across a certain solid cylindrical resistor, the current through it is 2 A. If the
1 answer:
Answer:
New Resistance = 0.5556 ohm
Explanation:
Resistance = resistivity * length /area
Here since resistivity and length are constant, we only need to see how the resistance increases or decreases with change in area.
New Area = pi * (3*D)^2 / 4
Old Area = pi * D^2 / 4
The ratio of new area / old area is :
Since area increases 9 times, and it is inversely proportional to resistance:
Resistance decreases by 9 times.
So, old resistance = Voltage / Current = 10 / 2 = 5 ohm
New Resistance = 5 / 9 = 0.5556 ohm (decreases by 9 times)
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Answer:
1.15 m/s
Explanation:
Part of the question is missing. Found the missing part on google:
"1. A hanging mass of 1500 grams compresses a spring 2.0 cm. Find the spring constant in N/m."
Solution:
First of all, we need to find the spring constant. We can use Hooke's law:
where
is the force applied to the spring (the weight of the hanging mass)
x = 2.0 cm = 0.02 m is the compression of the spring
Solving for k, we find the spring constant:
In the second part of the problem, the spring is compressed by
x = 3.0 cm = 0.03 m
So the elastic potential energy of the spring is
This energy is entirely converted into kinetic energy of the cart, which is:
where
m = 500 g = 0.5 kg is the mass of the cart
v is its speed
Solving for v,