Question

Поезд массой 2000 т, движущийся со скоростью 36 км/ч, остановился, пройдя путь 400 м. Определите величину тормозящей силы.

Answer 1

Ответ:

S=

2a

v

2

−v

0

2

; v=0; S=

2a

−v

0

2

; a=−

2S

v

0

2

<br/>F=ma=−

2S

mv

0

2

=−

2∗400

2000000∗10

2

=−25000 (H)=−25 (kH)

Answer 2

Calculation of the Braking Force

To determine the magnitude of the braking force, we can use the equation:

Braking force = mass × acceleration

In this case, the mass of the train is given as 2000 tons, and the train comes to a stop after traveling a distance of 400 meters. We need to find the acceleration to calculate the braking force.

To find the acceleration, we can use the equation:

Final velocity^2 = Initial velocity^2 + 2 × acceleration × distance

The initial velocity is given as 36 km/h, which needs to be converted to m/s. We can use the conversion factor 1 km/h = 0.2778 m/s.

Let's calculate the acceleration first:

Final velocity = 0 m/s (since the train comes to a stop)

Initial velocity = 36 km/h × 0.2778 m/s = 10 m/s

Distance = 400 m

0^2 = 10^2 + 2 × acceleration × 400

Simplifying the equation:

0 = 100 + 800 × acceleration

-100 = 800 × acceleration

acceleration = -100/800 = -0.125 m/s^2

Now that we have the acceleration, we can calculate the braking force:

Braking force = mass × acceleration

Braking force = 2000 tons × 1000 kg/ton × -0.125 m/s^2

Simplifying the equation:

Braking force = -250,000 N

Therefore, the magnitude of the braking force is 250,000 N.

Please note that the negative sign indicates that the force is acting in the opposite direction of motion, which is necessary to bring the train to a stop.