Answer:
B. 14.4 N
Rotational speed (Angular Velocity) = 2
The Radius of the circle = 1.2 m
Velocity = Angular velocity × radius = 2×1.2 = 2.4 m/s
Centripetal force= mv²/r = 3 × 2.4×2.4/1.2 = 3 × 2.4 × 2
= 14.4 N
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Answer:
The slope of a position-time graph can be calculated as:

where
is the increment in the y-variable
is the increment in the x-variable
We can verify that the slope of this graph is actually equal to the velocity. In fact:
corresponds to the change in position, so it is the displacement, 
corresponds to the change in time
, so the time interval
Therefore the slope of the graph is equal to

which corresponds to the definition of velocity.