Question

a motorbike running at 90 km per hour is slow down to 54 km per hour by the application of brakes over a distance of 40 metre if the brakes are applied with the same force calculate the
(i) total time in 20 about comes to rest
(ii) Total distance covered by the bike


Plss ans fast ​

Answer 1

Answer:

i)5 seconds

ii)62.5 m

Explanation:

Given:

u=90km/s= 25m/s

v= 54km/s= 15m/s

s=40 m

Solution:

v^2-u^2=2as

(15)^2-(25)^2=2×a×40

225-625=80a

80a= -400

a= -5m/s^2

i)Time taken to rest:

Now v= 0

u= 25m/a

a= -5m/s^2

v=u+at

0=25-5×t

t= 25/5

t= 5 seconds

ii)Total distance covered by bike:

v^2-u^2=2as

0-(25)^2=2×-5×s

-625. = -10s

s= 62.5

HOPE IT WILL HELP YOU

Answer 2

Explanation:

•Given

v = 54 kmh = 25 ms

u = 90 kmh = 15 ms

s = 40 m

v^2 - u^2 = 2as

(15)^2 - (25)^2 = 2a × 40

225 - 625 = 80a

400 / 80 = a

a = 5ms

v^2 - u^2 = 2as

(0)^2 - (25)^2 =2 × 5 × s

625 = 10 s

625 / 10 = s

s = 62.5 m