Suppose you throw a rock off a cliff on earth with an initial horizontal velocity of 3 m/s. assuming minimal drag and no wind, the horizontal velocity of the rock a. increases as it falls. b. decreases as it falls. c. is 0 m/s just before it lands. d. remains constant throughout the fall.

D. remains constant throughout the fall.

Explanation:

Horizontal Launching

We can launch an object in free air in three forms: vertically, horizontally or inclined. In any case, the only acting force to modify the object's velocity and make it go back to the ground is the force of gravity and it's always directed downwards. Unless friction or air resistance is considered, the horizontal motion is not affected because no force is acting in that direction.

The rock described in the question was launched at 3 m/s pointed horizontally. Immediately after launching, the rock starts to fall to the ground and gain vertical velocity, but the horizontal component remains the same until it completes the flight.  

The D option is correct: the horizontal velocity of the rock remains constant throughout the fall

pe = weightxheight = 2000x1000=2,000,000joules

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.