An open train car, with a mass of 2150 kg, coasts along a horizontal track at the speed 2.83 m/s. The car passes under a loading chute and, as it does so, gravel falls vertically into it for 2.95 s at the rate of 481 kg/s. What is the car's speed v f after the loading is completed? Ignore rolling friction.

The car's final speed after the loading is completed is 1.71 m/s

Explanation:

Given;

mass of the open car, m₁ = 2150 kg

initial speed of the car, u = 2.83 m/s

loading rate of the gravel, m' = 481 kg/s.

loading time of the gravel, t = 2.95 s

Then, mass of the gravel, m₂ = m' x  t  = 481 x 2.95 = 1418.95 kg

To determine the car's speed after the loading is completed, we apply the principle of conservation of linear momentum;

Initial momentum = Final momentum

m₁u = v(m₁ + m₂)

where;

v is the car's final speed after the loading is completed

2150 x 2.83 = v (2150 +  1418.95)

6084.5 = 3568.95v

v = 6084.5 / 3568.95

v = 1.71 m/s

Thus, the car's final speed after the loading is completed is 1.71 m/s

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force