An iron core is needed in an electromagnet because it serves to increase the magnetic field created. It has a ferromagnetic properties. <span>An </span>electromagnet<span> is essentially just a battery attached to a coil of wire wrapped around a metal</span>core<span>. </span>
Answer:
B) Physical properties cannot be observed without changing the identity of the material.
Answer:5.62 m/s
Explanation:
Given
Inclination 
Coefficient of kinetic Friction 
mass of Anissa's 
time interval 
acceleration of the system




where v=Final Velocity
u=Initial Velocity
a=acceleration of system
t=time
