A magnetic field is a force field, invisibly pushing electrically charged objects just as a gravitational field pulls objects with mass. Whereas all objects with mass exert a gravitational field, however, not all objects have a magnetic field. Magnetic fields are created by electrical charges. Thanks to their structure at the atomic level, some substances -- like the iron in magnets -- have a permanent magnetic field.
Answer:
frictonal force due to the surface of irregularities
<span>Which of the following forms of electromagnetic waves is LEAST dangerous to the human body? B
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Answer:
15.45 m/s
Explanation:
F = 1.2 x 10^3 N, Fk = 615 N, u = 0, s = 25 m
Let the speed after traveling 25 m is v.
mass = F / g = 1200 / 9.8 = 122.45 kg
Net force, Fnet = 1.2 x 1000 - 615 = 1200 - 615 = 585 N
acceleration = Fnet / mass = 585 / 122.45 = 4.78 m/s^2
Use third equation of motion
v^2 = u^2 + 2 a s
v^2 = 0 + 2 x 4.78 x 25 = 238.88
v = 15.45 m/s
