Response:
In the second scenario
Clarification:
Reasoning:
Friction opposes motion.
In scenario one, the block glides without any friction present, indicating a smooth surface allowing minimal net force to pull the string.
In the second scenario, kinetic friction plays a role between the sliding block and the table, where kinetic friction is expressed as:
with relevant variables being as the coefficient of friction and N as the normal force.
This means the necessary net force becomes:
Thus, the force is greater in the second situation.
Consequently, the tension is also heightened in the second scenario.
Response:
The new resistance is half of the original resistance.
Explanation:
Resistance in a wire is represented by:
= resistivity of the material
L and A are the physical dimensions
If a wire is exchanged for one where all linear dimensions are doubled, i.e. l' = 2l and r' = 2r
The updated resistance of the wire can be calculated as follows:
The new resistance equals half of the original resistance. Thus, this provides the solution needed.
Answer:
31.4 mm²
Explanation:
The ability of a telescope or eye to gather light can be expressed by the formula,
where d signifies the diameter of the pupil.
In bright daylight, the usual size of the pupil is 3 mm.
Conversely, in darkness, the diameter typically enlarges to 7 mm.
This indicates an increase in light-gathering capacity.
Thus, the amount of light the eye can capture is 31.4 mm².