Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

ICSE Class 9 Answered

A train starts from rest and accelerates uniformly at A rate of 2ms-1 for 10-s.It then maintains A constant speed for 200 s. Tge brakes are then applied and the train is uniformly retarded and comes to rest in 50 s. Find (i) the maximum velocity reached(ii) the retardation in the last 50 s (iii) the total distance travelled, and (iv) the average velocity of the train. 
Asked by taniadebsingha | 20 May, 2021, 09:34: PM
answered-by-expert Expert Answer
Starting from rest , if accelerated for 10 s with acceleration 2 m/s2 ,
then velocity after 10 s is determined from the following equation
 
v = a × t  = 2  ×  10  = 20 m/s
 
Distance travelled in 10 s ,  S1 = (1/2) a t2 = 0.5 × 2 × 10 × 10 = 100 m
 
Distance travelled in 200 s,  S2 =  velocity × time = 20 × 200 = 4000 m
 
Let ar be the retardation to stop the train in 50 s , then retardation is detrimined from
 
v - ( ar × t ) = 0    or   ar = v / t  = 20 /50  = 0.4 m/s2
 
Distance travelled in 50 s ,  S3 = ( v × t ) - ( 1/2) × ar × t2 
 
S3 = ( 20 × 50 ) - ( 0.5 × 0.4 × 50 × 50 ) = 500 m
 
Answers :-
 
(i) Maximum velocity = 20 m/s
 
(ii) Retardation in last 50 s  = 0.4 m/s2
 
(iii) Total distance = S1 + S2 + S3 = 100 + 4000 + 500 = 4600 m
 
(iv) average velocity = net Displacement / total time = 4600 / (10+200+50) = 17.69 m/s
 

Answered by Thiyagarajan K | 21 May, 2021, 08:13: AM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
ICSE 9 - Physics
a particle of mass 50 gram moving with a velocity of 10 ms¹ after 5s its velocity becomes 18 ms¹then the acceleration is
Asked by mymunathabasum1 | 24 Apr, 2023, 06:06: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 9 - Physics
If a train moves 25km/sec and decrease to 15km/sec by applying brake in 5 sec then what will be the force of brake
Asked by sahuprabhat325 | 14 Dec, 2022, 08:39: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 9 - Physics
Laws of motion equations 
Asked by Ramprasadramoji | 05 Sep, 2022, 06:44: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 9 - Physics
plz solve urgently dear experts :
question image
Asked by savitamahajan202 | 09 Jul, 2022, 12:47: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 9 - Physics
a car moving with a velocity of 72 km h-1 is brought to rest by applying brakes in 15 seconds find the retardation of the car
Asked by 2014.476bavyashree | 23 Jun, 2022, 06:00: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 9 - Physics
If car A is travelling at the speed of 80 km/h and car B at 60 km/h in the same direction, what is the velocity of the car A relative to the car B?
Asked by abhaymukherjee789 | 28 May, 2022, 11:06: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 9 - Physics
A train is moving with a velocity of 90 km hl. It is brought to stop by applying the brakes which produce a retardation of 0-5 m s2. Find: (i) the velocity after 10 s, and the time taken by the train to come to rest. Plot on graph
Asked by biswasdolly84 | 26 May, 2022, 09:55: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 9 - Physics
what is projectile motion
Asked by dibsparna | 03 Nov, 2021, 01:54: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 9 - Physics
all equations of motion?
Asked by kartikbhartiya613 | 28 May, 2021, 02:36: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
ICSE 9 - Physics
A train starts from rest and accelerates uniformly at A rate of 2ms-1 for 10-s.It then maintains A constant speed for 200 s. Tge brakes are then applied and the train is uniformly retarded and comes to rest in 50 s. Find (i) the maximum velocity reached(ii) the retardation in the last 50 s (iii) the total distance travelled, and (iv) the average velocity of the train. 
Asked by taniadebsingha | 20 May, 2021, 09:34: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt
Get Latest Study Material for Academic year 24-25 Click here
×