PLZZ solve this problem...
Answers
✒ v = 20 m/s
✒ a = - 0.4 m/s²
✒ s = 4600 m
✒ Avv = 17.69 m/s
✒ Accelerates 2 m/s in 10 second
✒ Constant speed for 200 second
✒ Come in rest in 50 second
1. The maximum velocity reached.
2. Retardation in last 50 seconds.
3. Total distance travelled.
4. The average velocity of train.
⭐First of all we have 3 cases/values in question. (we need them later)
* t1= 10 , u1 = 0 , v1 = 20 , a = 2
* t2= 200 , v = v1 = 20 , a = 0
* t3= 50 , u2 = v = 20 , v2=0 , a = - 0.4
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1) We know that, a = v-u/t
So, Substituting the values
2 = v - 0 / 10
v = 20 m/s (Above values) is the
maximum velocity reached.
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2) We know that, a = v-u/t
So,bSubstituting the values
a = 0 - 20 / 50
a = - 0.4 m/s² is the acceleration in last 50 seconds.
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3) Total Distance travelled = Distance in
case 1 + case 2 + case 3
✏ case 1. (using 3rd eq. Of motion)
=> 2as = v² - u²
= 2(2)s = (20)² - (0)²
= 4s = 400
= s = 400÷4
=> s = 100 m
✏ case 2. (using 2nd eq. Of motion)
=> s = ut + ½ at²
= s = (20)(200) + ½ (0)(200)²
= s = 4000 + 0
=> s = 4000 m
✏ case 3. (using 3rd eq. Of motion)
=> 2as = v² - u²
= 2(-0.4)s = (0)² - (20)²
= (-0.8)s = - 400
= s = 4000÷8
=> s = 500 m
Now, (100 + 4000 + 500) m
=> 4600 m is the total distance.
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4) Average velocity = Toatal Displacement/Total time (s/t>
*Total Displacement = 4600
*Total Time = 260 second
So, Substituting the values
=> 4600÷260
=> 17.69 m/s is the average velocity of train.
⭐Avv = Average Velocity
⭐ u = Initial velocity
⭐ v = Final velocity
⭐ a = Retardation (here use)
⭐ t = Time
Answer:
Total distance covered(a) = Distance during acceleration(s) + distance during uniform motion(sz) + distance during retardation(sz)
For acceleration,
v = u +at
Vmax = 2 x 10 = 20 m/s
s=ut + (1/2)at?
S1 = (1/2) x 2 x 10²
= 100 m
For uniform motion,
S = vt
S2 = 20 x 200
= 4000 m
During retardation, v = u + at
0= 20 + 50t
= -0.4 m/s2
S3 = ut + (1/2)at?
= 20 x 50 + (1/2) x (-0.4) x 502
= 500 m
Total distance travelled, s = sl + s2 + s3 =
100 + 4000 + 500 4600 m
Total time taken, t=tı + t2 + t3 = 260 s
Average velocity, Vavg =
Total Distance
Total Time
= 4600/260 = 17.69 m/s
Explanation: