Question

answer it fast plz ​

Answer 1

u=0 (from rest)

s=400m

t= 20s

a=?

by kinematic equation we have

s= ut + 1/2at^2

400 = 0(20) +1/2(a)(20)^2

400 = 1/2(a)(400)

a = 400 × 2/ 400

a = 2 m/ s^ 2.........(1)

F= ma

m=7000kg(Since 1 tonne = 1000kg)....(2)

from (1) & (2) we have

F=7000(2)

F=14000N

Hope u understood it clearly........

If it really helps u then don't forget to mark me as a brainlist..........

Answer 2

u=0m/s

t=20sec

s=400m

a=?

(Using 2nd equation of motion)

$s = ut + \frac{1}{2} a{t}^{2}$

400 =0(20) + 1/2a(20)(20)

400 = 200a

$a = 2 \frac{m}{ {s}^{2} }$

Force acting on it = Mass × Acceleration

= 7000kg × 2m/s*s

= 14000 N