Understanding Capacitor Charging Time

In summary, the person is struggling with a problem that involves finding the value of ln -.3. They have attempted to solve it but have not been successful. They ask for assistance and someone suggests canceling out the -1 on both sides of the equation. They also mention having another problem with different answers.
  • #1
pat666
709
0

Homework Statement



Please see the attachment
ok I am really not very good with this stuff at the moment. From reading the text I have gotten somewhere but have obviously screwed it up. ln -.3 doesn't exist obviously. Please help me with this. thanks

Homework Equations





The Attempt at a Solution


attempt can be seen in the same attachment as question. again I really need help with this..
 

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  • #2
You have on the left side near to the end

0.7-1 = -e t

0.7-1 is -0.3

so you will end up with something like -0.3=-et. The -1s cancel.
 
  • #3
oh ok thanks - is this the right procedure?
 
  • #4
Yes it should be.
 
  • #5
thanks - do you know what's going on with my other problem that we had different answers to?
 

1. How do you calculate the time it takes to charge a capacitor?

The time it takes to charge a capacitor can be calculated using the formula t = RC, where t is the time in seconds, R is the resistance in ohms, and C is the capacitance in farads.

2. What factors affect the time it takes to charge a capacitor?

The time it takes to charge a capacitor can be affected by the resistance of the circuit, the capacitance of the capacitor, and the voltage of the power source.

3. Can the time it takes to charge a capacitor be shortened?

Yes, the time it takes to charge a capacitor can be shortened by using a lower resistance or a higher voltage power source. Additionally, using a capacitor with a higher capacitance can also reduce the charging time.

4. How does the type of capacitor affect the charging time?

The type of capacitor can affect the charging time due to its internal resistance and dielectric material. Capacitors with lower internal resistance and higher dielectric constants will typically charge faster.

5. What is the significance of the time constant in charging a capacitor?

The time constant, represented by the symbol τ (tau), is the time it takes for the capacitor to charge to approximately 63% of its maximum charge. It is a crucial factor in determining the charging time of a capacitor and can be used to predict the charging behavior of the capacitor in different circuits.

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