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7 votes
7 votes
a car moving with a velocity of 54km/h accelerate uniformly at the rate of 2m/s².Calculate the distance travelled from place where acceleration bagans to where the velocity reaches 72km/h and the time taken to cover the distance​

User Cube
by
3.3k points

2 Answers

14 votes
14 votes

ANSWER: 234.4 m and 2.5 seconds

Step-by-step explanation:

1. List what we have.


v_f = 72 km/h=20 m/s


v_i = 54 km/h = 15 m/s


a = 2 m/s^2

2. Find time first.


t = (v_f - v_i)/(a)


t = (20 - 15)/(2)


t= 2.5 seconds

2. Then find the distance.


s = v_i t (1)/(2) a t^2


s = (15)(2.5)(1)/(2) (2)(2.5)^2


s = 234.4 m

btw, I'm not good at physics AT ALL so this is just me guessing and trying to help

22 votes
22 votes
let's first convert km/hr into m/s
54 km/hr : 15m/s
72 km/hr : 20m/s
Applying :
v
2

u
2
=
2
a
S
v
2
−u
2
=2aS
20
×
20

15
×
15
=
2
×
2
×
S
S
=
175
/
4
=
43.75
m
20×20−15×15=2×2×S
S=175/4=43.75m
User Jonsmoke
by
2.8k points