Ana kicks a stationary 0.2kg soccer ball. The ball leaves her foot at a speed of 20 m/s. A. What impulse was delivered to the ball?
B. The ball experience 40N of force during the kick. How long were the ball and foot in contact?

a. 24 kg m/s

b.  3/5s

Explanation:

a.impulse is the change in momentum so at first the momentum is zero because the ball was at rest and the final momentum is 1.2kg*20m/s=24 kg m/s

so the impulse would be (24-0) kg m/s=24 kg m/s

b. so the impulse equation is impulse is force *delts time

so 24 kg m/s=40N*t

t=24 kg m/s /40N=3/5 s

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia