Answer:
hope this helps i think the answer is C
Answer:
Max speed = 
Max acceleration = 
Explanation:
Given the description of period and amplitude, the SHM could be described by:

and its angular velocity can be calculated doing the derivative:

And therefore, the tangential velocity is calculated by multiplying this expression times the radius of the movement (3 m):
and is given in m/s.
Then the maximum speed is obtained when the cosine function becomes "1", and that gives:
Max speed = 
The acceleration is found from the derivative of the velocity expression, and therefore given by:

and the maximum of the function will be obtained when the sine expression becomes "-1", which will render:
Max acceleration = 
The transfer of heat through flowing material is convection
Answer: The correct answer is zero work done.
Explanation:
Work is said to be done when the object moves through a distance when the force is applied to the object.
If the object does not move a distance even the force is exerted on the object then the work done is zero in this case.
Therefore, when the force is exerted even when no work is done then this is called zero work done.
Answer:
B) Tommy had a positive acceleration between noon and 12:30 pm.
Explanation:
Acceleration is defined as the rate of change of velocity:

where
v is the final velocity
u is the initial velocity
t is the time
In the problem,
- At noon, Tommy is walking at a velocity of 4 mi/h
- At 12.30 pm, Tommy is walking at a velocity of 6 mi/h
- A time of half an hour (0.5 h) passed between the two moments
So Tommy's acceleration is

and the acceleration is positive, since the velocity has increased.