Ask a Doubt
Request a call back

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

CBSE Class 9 Answered

A car is travelling at 20 m/s along a road. A child runs out into the road 50m ahead and the cardriver steps on the break pedal. WHAT MUST THE CAR'S DECELERATION BE IF THE CAR IS TO STOP JUST BEFORE IT REACHES THE CHILD??????????????????????????

Asked by Prachi Jha | 12 May, 2014, 04:45: PM
answered-by-expert Expert Answer
Initial velocity of the car, u=20 m/s
Final velocity of the car, v=0 m/s
Distance cover by the car, s=50 m
Let the constant decelaration due to the breaks be 'a',
By using equation,
v2-u2=2 a s
0 - 400 = 2 x a x 50
-400 = 100 a
a = -4 m/s
The acceleration of the car is -4 m/s.
Answered by Faiza Lambe | 13 May, 2014, 12:07: PM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
CBSE 9 - Physics
why is it necessary for acceleration to be based on velocity but not on speed? why we dont consider the increasing speed of rectilinear motion as acceleration? why is it so in the first place?
Asked by kempersi267k | 01 Jul, 2022, 06:36: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
what is retardation
Asked by hd2583188 | 02 Jun, 2022, 05:04: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
True or false: The motion of a freely falling body is an example of uniformly accelerated motion.
Asked by juhi.panchal | 05 May, 2022, 11:26: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
A car increases it’s speed from 36km/h to 54km/h in 2s Find Distance travelled by the car
Asked by grangerhermione951 | 02 Dec, 2021, 08:32: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
A Car with an initial speed of 1 m/sec was in motion for 10 minutes, and then it came to a stop, the velocity right before it stopped was 5 m/sec. What was the constant acceleration of the car?  
Asked by psdarshan25082007 | 08 Sep, 2021, 08:14: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
A boy travelling in a car at a speed of 108Km/h came to rest after applying breaks. Before coming to rest it covers 30m. It's acceleration is
Asked by 2103030034 | 28 Aug, 2021, 03:06: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
A force acts for 10 secs on a stationary body of mass 100kg after which the force ceases to act. The body moves through a distance of 100m in the next 5 secs. Calculate:- i) the velocity acquiured by the body ii) the acceleration producced by the force iii) the magnitude of the force
Asked by atmojyotibarman7 | 30 Jul, 2021, 03:27: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
use the below v-t graph calculate, (a)the acceleration of the body as it moves from 0 to A (b)the distance covered by the body from o to a c THE acceleration of the body from B TO C
question image
Asked by vikaashrajan11 | 28 Jul, 2021, 09:55: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
A train starting from rest attains a velocity of 72 km/hr in 5 minutes. Assuming that the acceleration is uniform find the acceleration. *
Asked by jainpranav33047 | 20 Jul, 2021, 09:28: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 9 - Physics
Give one example for each of the type of motion when i) Acceleration is in the direction of motion ii) Acceleration is against the direction of motion iii) Acceleration is uniform
Asked by ansh231206bhatia | 29 May, 2021, 03:42: 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
×