I need help to solve this problem. It's one problem but it has multiple parts

4. [0/3 Points] DETAILS PREVIOUS ANSWERS SERPSE10 15.5.OP.026. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A simple pendulum is 9.00 m long. (a) What is the period of small oscillations for this pendulum if it is located in an elevator accelerating upward at 4.00 m/s2? 7.78 X This period is greater than the period found if the elevator is at rest. Does this make sense? s (b) What is the period of small oscillations for this pendulum if it is located in an elevator accelerating downward at 4.00 m/s? 5.06 X This period is less than the period found if the elevator is at rest. Does this make sense? s (c) What is the period of this pendulum if it is placed in a truck that is accelerating horizontally at 4.00 m/s? 4.00 X One way to work in a uniformly accelerating reference frame is to consider the force of gravity to have an extra component equal to -ma. What is the magnitude of the effective force of gravity in this case? s