Question

if r = 40t i +(30t-5t^2) j ii)find displacement at 2 seconds ii)velocity at 2 sec

Answer 1

Answer:

r = 89.44 m

v = 41.23 m/s

Explanation:

r = 40t i +(30t-5t^2) j

at t= 2 sec

r = 40*2 i + ( 30*2 -5*4 ) j

r = 80 i + 40 j

r = sqrt ($80^{2}$ + $40^{2}$)

r = sqrt ( 6400 + 1600 )

 = 89.44 m

v= d/dt ( 40t i +(30t-5t^2) j )

 = 40 i + (30 -10t ) j

at t= 2 sec

 = 40i  + 10 j

v = sqrt ( 40sqr + 10 sqr )

  = sqrt ( 1600 + 100 )

v = 41.23 m/s

Answer 2

Answer:

cal training of A 26 multiply divided into number 24 2.4 ad4 36.7