Answer:
a) 10^6 m/s^2
b) 7.39 s
Step-by-step explanation:
Hello!
If the velocity is given by:
![v(t) = c_1 + c_2 t^2](https://img.qammunity.org/2020/formulas/physics/high-school/hlhe352ler2v1mhfhbhfb5amm5pqmzb88m.png)
Then the acceleration is the derivative of the velocity with respect of time:
![a(t) = 2 c_2 t](https://img.qammunity.org/2020/formulas/physics/high-school/j55xpcew7416eo6stzgkb1te9a0mth9sjz.png)
a)
Therefore the acceleration at t=5.0s is:
![a(5.0s) = 2 c_2 * 5.0 = 10^6 m/s^2](https://img.qammunity.org/2020/formulas/physics/high-school/xw6pc8t7iu1jfd2cks521bulabvn2akas7.png)
b)
The velocity will become unphysical when it equals the velocity of ligth (3x10^8 m/s)
3x10^8 m/s = 2x10^5 m/s + 10^5 m/s^3 t^2
Solving for t:
t^2 = 2998 s^2
t = 7.39 s