Question

2. A particle starts from rest, accelerates at
2m/s for 10s and then goes for constant Spred for 30s and
then decelerated at 2m/s till it stop what is the
distance travelled by it​

Answer 1

Answer:

Explanation:

Case 1 : initial velocity,u = 0m / s

Acceleration,a = 2m/s²

Time = 10 sec

Final velocity, v = ?

Distance travelled ,S1= ?

v = u+at

v = 0 + 2× 10

v = 20 m/ s

S1 = ut+ 1/2 at²

S1 = 0 + 1/2 ×2 × 100

S1 = 100m

Case 2: speed = 20m /s

Time taken = 30 sec

Distance travelled,S2 = speed × time taken

= 600m

Case 3 : in this case the initial velocity will be the final velocity obtained in case 1

Initial velocity, u= 20m/s

Acceleration ,a= - 2m/s²

Final velocity,v = 0m/s

Distance travelled, S3 = ?

v²= u² + 2 a S3

0 = 400 - 4 S3

S3 = 100m

Total distance covered in the whole journey = S1 + S2+S3

= 100m + 600m +100m

= 800m