The MRT train starting at an initial velocity of 30 kph travels a distance of 21km in 18 minutes. Determine the acceleration of the train at this instant in m/s^2.
vf^2 = vo^2 + 2a*distance change 18 min to seconds, km to meters 30kph to m/s
and solve for a.
0.0865 m/s˄2
To determine the acceleration of the train, we can use the equation of motion:
\(\text{Acceleration} (a) = \frac{{\text{Change in velocity} (v)}}{{\text{Change in time} (t)}}\)
Given:
Initial velocity (\(u\)) = 30 kph
Distance (\(s\)) = 21 km
Change in time (\(t\)) = 18 minutes
First, let's convert the initial velocity and distance to meters and change the time to seconds for consistent units.
Initial velocity (\(u\)) = 30 kph = 30 × \(\frac{1000}{3600}\) m/s = 8.33 m/s (approximately)
Distance (\(s\)) = 21 km = 21 × 1000 m = 21000 m
Change in time (\(t\)) = 18 minutes = 18 × 60 s = 1080 s
Next, we can calculate the change in velocity (\(v\)) using the formula:
\( v = \frac{s}{t} \)
\( v = \frac{21000}{1080} \) m/s
\( v = 19.44 \) m/s (approximately)
Finally, substituting the values into the formula for acceleration:
\( a = \frac{v - u}{t} \)
\( a = \frac{19.44 - 8.33}{1080} \) m/s²
\( a = \frac{11.11}{1080} \) m/s²
\( a \approx 0.01028 \) m/s² (approximately)
Therefore, the acceleration of the train at this instant is approximately 0.01028 m/s².
To determine the acceleration of the train, we need to use the formula:
acceleration = change in velocity / time
First, let's convert the initial velocity from kph to m/s:
30 kph = 30 * (1000/3600) m/s = 8.33 m/s
Next, we need to determine the final velocity. We know that the train traveled a distance of 21 km in 18 minutes. Let's convert that to meters and seconds for consistent units:
21 km = 21000 m
18 minutes = 18 * 60 seconds = 1080 seconds
To find the final velocity, we can use the formula:
final_velocity = initial_velocity + (acceleration * time)
In this case, the initial velocity is 8.33 m/s, and the time is 1080 seconds. We want to solve for the final velocity, so rearranging the formula gives us:
final_velocity = initial_velocity + (acceleration * time)
final_velocity = 8.33 m/s + (acceleration * 1080 seconds)
Since the train starts at rest, the final velocity is the velocity at this instant. Therefore, we have:
8.33 m/s + (acceleration * 1080 seconds) = final_velocity
Now, let's use the formula to find the acceleration:
acceleration = (final_velocity - initial_velocity) / time
acceleration = (final_velocity - 8.33 m/s) / 1080 seconds
We are given that the train traveled a distance of 21 km, which means it came to a stop at the end. When the train comes to a stop, the final velocity is zero. Therefore, we have:
(0 m/s - 8.33 m/s) / 1080 seconds = acceleration
Calculating this expression, we find:
acceleration = -8.33 / 1080 m/s^2
Therefore, the acceleration of the train at this instant is approximately -0.0077 m/s^2. The negative sign indicates that the train is decelerating.