Answer:
the primary coil current produces a magnetic field, which changes as the current changes. the iron core increases the strength of the magnetic field. the changing magnetic field induces a changing potential difference (voltage) in the secondary coil.
-- An object acted on by only the force of gravity, on or near Earth's surface,
accelerates downward at the rate of about 9.8 m/s² without air resistance.
-- That number is "the acceleration due to gravity, on Earth".
-- The object in that situation is said to be in "free fall".
Answer:
Forces Due to Friction and Newton's Third Law
The forces on the cart include the forward force the horse exerts on the cart and the backward force due to friction at the ground, acting on the wheels. At rest, or at constant velocity, these two are equal in size, because the acceleration of the cart is zero.
