A 21.2-kg object is being pulled in one direction by a force of 68.8 N while a force of 26.5 N pulls in the opposite direction. What is the acceleration of the object

The net force is in the direction of the larger force. If we take that direction to be positive, then the net force has a magnitude of

68.8 N - 26.5 N = 42.3 N

Use Newton's second law to solve for the acceleration:

F = m a

42.3 N = (21.2 kg) a

a = (42.3 N) / (21.2 kg)

a ≈ 2.00 m/s²

(you might also try 1.99 or 2.01 in case that doesn't get accepted)

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.

the journeys of marquette, joliet and la salle a) new france expand.

all three of these explorers explored the midwest and the area around the great lakes, which they subsequently claimed for france.

this was a big portion of territory and expanded new france which before then only consisted of quebec province in northeastern canada