Find the best solutions to your problems with the help of IDNLearn.com's expert users. Discover thorough and trustworthy answers from our community of knowledgeable professionals, tailored to meet your specific needs.

a) [tex]\(12.5 \, \text{km}\)[/tex]

b) [tex]\(91.4 \, \text{km}\)[/tex]

c) [tex]\(11.3 \, \text{km}\)[/tex]

d) [tex]\(49.2 \, \text{km}\)[/tex]

Given:
[tex]\[ d = V \cdot t \][/tex]
[tex]\[ 45 \, \text{m} \cdot \frac{60 \, \text{s}}{1 \, \text{m}} - 2 \][/tex]
[tex]\[ 15 \, \text{km/h} = 11.30 \][/tex]

5. A train travels at [tex]\(60 \, \text{km/h}\)[/tex]. Immediately after passing a red signal, it begins to come to a complete stop over a distance of 150 meters. Determine its acceleration.

a) [tex]\(-0.5 \, \text{m/s}^2\)[/tex]


Sagot :

Sure, let's solve the problem.

Question:
A train travels at a speed of 60 km/h. Immediately after passing a red signal, it starts to come to a complete stop within a distance of 150 meters. Determine its acceleration.

Solution:

1. Initial Information:
- Initial velocity ([tex]\(u\)[/tex]) = 60 km/h
- Stopping distance ([tex]\(s\)[/tex]) = 150 meters

2. Convert the initial velocity from km/h to m/s:
- To convert km/h to m/s, you can use the formula:
[tex]\[ \text{Velocity in m/s} = \left( \frac{\text{Velocity in km/h} \times 1000}{3600} \right) \][/tex]
- Plugging in the values:
[tex]\[ u = \frac{60 \times 1000}{3600} = 16.67 \text{ m/s} \][/tex]

3. Use the kinematic equation to find the acceleration:
- The kinematic equation which relates initial velocity, final velocity, acceleration, and distance is:
[tex]\[ v^2 = u^2 + 2as \][/tex]
- Here, final velocity ([tex]\(v\)[/tex]) is 0 because the train comes to a stop.
- Rearrange to solve for acceleration ([tex]\(a\)[/tex]):
[tex]\[ 0 = u^2 + 2as \implies a = -\frac{u^2}{2s} \][/tex]
- Substitute the known values into the equation:
[tex]\[ a = -\frac{(16.67)^2}{2 \times 150} \approx -0.93 \text{ m/s}^2 \][/tex]

Answer:
The acceleration of the train is approximately [tex]\(-0.93 \text{ m/s}^2\)[/tex].

This solution accounts for the initial velocity conversion and the application of the kinematic equation to determine the train's deceleration as it stops after passing the red signal.