A. 90km/h = 25 m/s
W=1/2mv^2
=1/2* 650* 25^2
= 203125(J)
b. v’= 90-50= 40km/h
= 100/9 m/s
W=1/2mv^2
=1/2*650*(100/9)^2
= 40123,45679
Trust vs. mistrust is the first stage in Erik Erikson's theory of psychosocial development. This stage begins at birth continues to approximately 18 months of age. ... If the care has been inconsistent, unpredictable and unreliable, then the infant may develop a sense of mistrust, suspicion, and anxiety.
Hope it is helpful
I believe this would be an example of Mary's velocity. We have her speed and direction which is all you need to find velocity.