Astudent wants you to demonstrate that an electric current will produce a magnetic field.

which set of objects could be used to demostrate this?
a) a battery, a coil of wire and a compass.
eliminate
b) a compass, some paper clips and a battery.
c) a battery, an iron nail and a long copper wire.
d) an iron nail, a permanent magnet and a battery.

A)A battery, a coil of wire and a compass.

Explanation:

When current flows through the coil it will produce magnetic field in the region of coil

This magnetic field is given by equation

here we know that

n = number of turns per unit length

I = current in the coil

So here we need

1). A coil of wire

2). A battery to produce current

Now this magnetic field is detected by a magnetic compass so next part we need is

3). Magnetic compass

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.