The angular position of objects as a function of time is given, where a, b, and care constants. In which of these cases is the angular acceleration constant? Select all correct answers (Hint: there is more than one.) Select one or more B. 0 - ar + b ii. O = ar?. btc ili. 8 - at? - iv. 0 = sin (at)

The options is not well presented

This are the options

A. θ = at³ + b

B. θ = at² + bt + c

C. θ = at² - b

D. θ = Sin (at)

So, we want to prove which of the following option have a constant angular acceleration I. e. does not depend on time

Now,

Angular acceleration can be determine using.

α = d²θ / dt²

α = θ'' (t)

So, second deferential of each θ (t) will give the angular acceleration

A. θ = at³ + b

dθ/dt = 3at² + 0 = 3at²

d²θ/dt² = 6at

α = d²θ/dt² = 6at

The angular acceleration here still depend on time

B. θ = at² + bt + c

dθ/dt = 2at + b + 0 = 2at + b

d²θ/dt² = 2a + 0 = 2a

α = d²θ/dt² = 2a

Then, the angular acceleration here is constant is "a" is a constant and the angular acceleration is independent on time.

C. θ = at² - b

dθ/dt = 2at - 0 = 2at

d²θ/dt² = 2a

α = d²θ/dt² = 2a

Same as above in B. The angular acceleration here is constant is "a" is a constant and the angular acceleration is independent on time.

D. θ = Sin (at)

dθ/dt = aCos (at)

d²θ/dt² = - a²Sin (at) = - a²θ

α = d²θ/dt² = - a²θ

Since θ is not a constant, then, the angular acceleration is dependent on time and angular displacement

So,

The answer is B and C