A fruit bat falls from the roof of a cave. We know that her potential energy was
1 answer:
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Answer:
J = 12.32kg*m/s
Explanation:
Assumptions: I'm assuming mis is m/s
Given: The baseball's mass is 140g, so convert to kg, 0.140kg. (Good rule of thumb, in physics convert grams to kilograms). It is initially traveling 35 m/s to the right.
When it hits the bat, it flies left with a velocity of 55 m/s at an angle of 25°. To reiterate:
mass = 0.140kg, Initial: 35m/s, Final: 55m/s at an angle of 25°
For this problem, we have to use the impulse equation, but before that lets break the velocity into components (It will be apparent towards the end):
The initial velocity is moving only in the horizontal direction, so:
The final velocity has an x and a y component:
Now the equation for impulse is (dp is Δp, which is difference in momentum; dv is Δv, the difference in velocity; J is impulse):
To get Δv, we have to find the difference of velocity, that is why we broke it into components. I'm going to define right as positive and left as negative. After that, we find the velocity vector:
Finally, substitute into the equation
J = 12.32kg*m/s
Answer:
Choice B: The current decreases.
Explanation:
The resistance of a conductor is proportional to its length when radius and resistivity stays the same. The resistance of the longer filament will be greater than the resistance of the initial one.
For Ohmic conductors,
,
where
is the current through the conductor,
is the voltage across the conductor, and
is the resistance of the conductor.
Voltage here stays the same. Increasing the resistance of the conductor will reduce the current.
The filament might heat up over time. The filament might not be an ohmic conductor. Still, a similar trend shall exist. Resistance will be greater in the longer filament, and current will decrease.