Question

À bus decreases its speed from 80 km/hr to 50km/hr in 4 seconds. Find the acceleration on the bus. How much distance is covered by the bus during that time?

Answer 1

here

v=50 km/h =50×5/18 =250/18 m/s

u =80 km/h=80×5/18=400/18 m/s

t=4 s

=

v-u =(250 -400 )/18= -150 /18 m/s

v-u = -25/3 m/s

now

acceleration a =(v-u)/t

a=(-25/3)/4

a= - 25/12

now distance is given by

S = u ×t - 1/2×a×t×t

S =(400/18)×4 - 1/2(25/3)×4×4

S =1600/18 - 25×16/6

S = 1600/18 - (400×3)/18

S= 400/18

S =200/9 m