A 100.0 kg safe is pushed across a floor with a force of 450 N. The coefficient of kinetic friction is 0.35. What is the acceleration of the safe?

1.07m/s²

Explanation:

From the question we are given the following

applied force Fapp = 450N

mass of the safe m = 100kg

Weight of the safe W = 980N

coefficient of kinetic friction n = 0.35

Required

Acceleration of the safe

According to Newton's second law

\sum Fx = ma

Fapp - Ff = ma

Ff is the frictional force

Fapp - nmg = ma

450 - 0.35(100)(9.8) = 100a

450 - 343= 100a

107 = 100a

a = 107/100

a = 1.07m/s²

Hence the acceleration of the safe is 1.07m/s²

uranium fissions/breaks up giving out energy and neutrons

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.