The momentum of an object is the product between the mass m of the object and its velocity:
The truck in our problem has momentum equal to
and a mass of
so, if we re-arrange the previous formula, we can use these data to find the velocity of the truck:
Answer:
3 s
Explanation:
velocity=initial velocity +a*t
34=10 + 8t
24=8t
t=3 s
The question is unclear regarding the boat's velocity. Is it 20 m/s south relative to the water, or relative to the earth? (It is a river, after all...)
There's also the possibility that the boat's velocity relative to the river is 0. Take the south direction to be negative and north to be positive, and denote by the velocity of a body A relative to a body B. Under these conditions,
(B for boat, E for earth, W for water) so that the passenger's velocity relative to the earth is
(P for passenger)
or 10 m/s south.
Intensity is the word you are looking for!