Answer:
The time constant is 1.049.
Explanation:
Given that,
Charge 
We need to calculate the time constant
Using expression for charging in a RC circuit
![q(t)=q_{0}[1-e^{-(\dfrac{t}{RC})}]](https://tex.z-dn.net/?f=q%28t%29%3Dq_%7B0%7D%5B1-e%5E%7B-%28%5Cdfrac%7Bt%7D%7BRC%7D%29%7D%5D)
Where,
= time constant
Put the value into the formula
![0.65q_{0}=q_{0}[1-e^{-(\dfrac{t}{RC})}]](https://tex.z-dn.net/?f=0.65q_%7B0%7D%3Dq_%7B0%7D%5B1-e%5E%7B-%28%5Cdfrac%7Bt%7D%7BRC%7D%29%7D%5D)





Hence, The time constant is 1.049.
Its resistor :}...............
Answer:
200000 J
Explanation:
From the question given above, the following data were obtained:
Mass (m) of roller coaster = 1000 Kg
Velocity (v) of roller coaster = 20 m/s
Kinetic energy (KE) =?
Kinetic energy is simply defined as the energy possess by an object in motion. Mathematically, it can be expressed as:
KE = ½mv²
Where
KE => is the kinetic energy.
m =>is the mass of the object
V => it the velocity of the object.
With the above formula, we can obtain the kinetic energy of the roller coaster as follow:
Mass (m) of roller coaster = 1000 Kg
Velocity (v) of roller coaster = 20 m/s
Kinetic energy (KE) =?
KE = ½mv²
KE = ½ × 1000 × 20²
KE = 500 × 400
KE = 200000 J
Therefore, the kinetic energy of the roller coaster is 200000 J.