Frame of reference, in simplest terms, describes the state of motion of the observer. The frame of reference may also be described by using a set of coordinates, time and motion. We formulate all our equations and solve them using the frame of reference.
Answer:
A moving electric charge creates a magnetic field at all points in the surrounding region.
An electric current in a conductor creates a magnetic field at all points in the surrounding region.
A permanent magnet creates a magnetic field at all points in the surrounding region.
Explanation:
Magnetic field can be produced by:
- moving charges (i.e. a moving electron, or a current in a conductor)
- A magnet
The strength of the magnetic field produced by a current-carrying wire is

where
I is the current
r is the distance from the wire
As we see from the formula, the magnetic field is produced at all points in the surrounding region, because B becomes zero only when r becomes infinite. The same is true for the magnetic field created by a single moving charge or by a magnet.
The following choices instead are not correct:
- A single stationary electric charge creates a magnetic field at all points in the surrounding region.
- A distribution of electric charges at rest creates a magnetic field at all points in the surrounding region.
Because they involve the presence of stationary charges, and stationary charges do not produce magnetic fields.
Answer:
Im pretty sure its B im very sorry if its wrong.
<h2>
The momentum is greater for 0.1 kg bullet traveling at 300 m/s</h2>
Explanation:
Momentum = Mass x Velocity.
A 2500 kg truck moving at 0.01 m/s
Momentum = Mass x Velocity
Momentum = 2500 x 0.01 = 25 kgm/s
A 0.1 kg bullet traveling at 300 m/s
Momentum = Mass x Velocity
Momentum = 0.1 x 300 = 30kgm/s
Momentum of 0.1 kg bullet traveling at 300 m/s > Momentum of 2500 kg truck moving at 0.01 m/s.
The momentum is greater for 0.1 kg bullet traveling at 300 m/s