Choose the statement(s) that are FALSE. A. An object will undergo constant acceleration if it is in equilibrium. B. Subject to the same net force, a larger mass will accelerate at a greater rate than a smaller mass. C. If the vector sum of the forces on an object is not zero, the object is in equilibrium. D. A net force of 125 N acts horizontally on an object that weighs 125 N. Therefore, the object does not accelerate. E. If an object is at rest, then there are no forces acting on the object. F. None of these statements are false.

A, B, C, D and E

Explanation:

A. An object will undergo constant acceleration if it is in equilibrium.

This is false because an object in equilibrium has no acceleration.  

B. Subject to the same net force, a larger mass will accelerate at a greater rate than a smaller mass.

This is false because, since F = ma and a = F/m where a is acceleration and m = mass. Since F is constant, a ∝ 1/m. So acceleration is inversely proportional to mass. So, the smaller mass would accelerate at a greater rate than the larger mass.

C. If the vector sum of the forces on an object is not zero, the object is in equilibrium.

This is false because an object can only be in equilibrium if the vector sum of the forces acting on it is zero.

D. A net force of 125 N acts horizontally on an object that weighs 125 N. Therefore, the object does not accelerate.

This is false because, the weight acts in the vertical direction and has no effect in the horizontal direction. The only forces in the horizontal direction are the frictional force and the 125 N horizontally applied force.

The objects accelerates if the 125 N applied force is greater than the frictional force and since frictional force = μN = μW where μ = coefficient of friction, N = normal force and W = weight of the object. Since μ < 1, f < W. So f < 125 N. So, the object accelerates.

E. If an object is at rest, then there are no forces acting on the object.

This is false because, an object might be at rest when the net force acting on it is zero not only when no force acts on it.

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.

god i hope this !