If you added enough ropes and pulleys to lift any size mass would it be possible to never have to apply a force to move your mas
2 answers:
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Answer:
mu = 0.56
Explanation:
The friction force is calculated by taking into account the deceleration of the car in 25m. This can be calculated by using the following formula:
v: final speed = 0m/s (the car stops)
v_o: initial speed in the interval of interest = 60km/h
= 60(1000m)/(3600s) = 16.66m/s
x: distance = 25m
BY doing a the subject of the formula and replace the values of v, v_o and x you obtain:
with this value of a you calculate the friction force that makes this deceleration over the car. By using the Newton second's Law you obtain:
Furthermore, you use the relation between the friction force and the friction coefficient:
hence, the friction coefficient is 0.56
Answer:
V = 4.81 V
Explanation:
- As the potential difference between the battery terminals, is less than the rated value of the battery, this means that there is some loss in the internal resistance of the battery.
- We can calculate this loss, applying Ohm's law to the internal resistance, as follows:
- The value of the potential difference between the terminals of the battery, is just the voltage of the battery, minus the loss in the internal resistance, as follows:
- We can solve for rint, as follows:
- When the circuit draws from battery a current I of 0.469A, we can find the potential difference between the terminals of the battery, as follows:
- As the current draw is larger, the loss in the internal resistance will be larger too, so the potential difference between the terminals of the battery will be lower.