Acceleration (magnitude anyway) = (change in speed) / (time for the change) .
Change in speed = (10 - 30) = -20 m/s
Time for the change = 4.0sec
Magnitude of acceleration = -20/4 = <em>-5 m/s² </em>
Answer: Primary coil
A Step-down transformer is an electrical device which is used to decrease the voltage using magnetic induction. The windings of the primary coil are more than the windings of the secondary coils. h1, h2 notations are used to refer to primary coils. On the other hand, x1, x2 notations are used to refer to the secondary coils of the transformer. In case of step-up transformer, the windings of primary coil are less than the secondary in order to increase the voltage.
I think the correct answer from the choices listed above is option C. As an object sinks in a fluid, the buoyant force increases before it is submerged and as the object is submerged the buoyant force stays the same. This can be explained by Archimedes principle.<span />
