Question

a car moving at speed 20 m/s stops in 40 sec the acceleration will be​

Answer 1

Explanation:

Initial speed of the car is u.

Initial speed of the car is u.Final speed of the car v=0

Initial speed of the car is u.Final speed of the car v=0Let the retardation of the  car be a.

Initial speed of the car is u.Final speed of the car v=0Let the retardation of the  car be a.Using  v2−u2=2aS

Initial speed of the car is u.Final speed of the car v=0Let the retardation of the  car be a.Using  v2−u2=2aSOr  0−u2=2aS

Initial speed of the car is u.Final speed of the car v=0Let the retardation of the  car be a.Using  v2−u2=2aSOr  0−u2=2aS⟹ S∝u2   (for same a)

Initial speed of the car is u.Final speed of the car v=0Let the retardation of the  car be a.Using  v2−u2=2aSOr  0−u2=2aS⟹ S∝u2   (for same a)Given :  S=40m    u′=2u

Initial speed of the car is u.Final speed of the car v=0Let the retardation of the  car be a.Using  v2−u2=2aSOr  0−u2=2aS⟹ S∝u2   (for same a)Given :  S=40m    u′=2u∴ SS′=u2(u′)2=22

Initial speed of the car is u.Final speed of the car v=0Let the retardation of the  car be a.Using  v2−u2=2aSOr  0−u2=2aS⟹ S∝u2   (for same a)Given :  S=40m    u′=2u∴ SS′=u2(u′)2=22Or  40S′=4

Initial speed of the car is u.Final speed of the car v=0Let the retardation of the  car be a.Using  v2−u2=2aSOr  0−u2=2aS⟹ S∝u2   (for same a)Given :  S=40m    u′=2u∴ SS′=u2(u′)2=22Or  40S′=4⟹  S′=160m

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Answer 2

Answer:

acceleration = - 2m/s

Explanation:

Initial speed (u) = 20 m/s

Final speed (v) = 0

Time = 40 sec

v = u + at

0 = 20 + a(40)

-20 = a(40)

a = -20/40

a = - 2 m/s

HOPE IT HELPS