Answer:
here given is a weight
then force becomes mg
that is F=Mg
=4*9.8
then by using the formula
F=Ma
a=F/M
=4*9.8/9.8
=4
Explanation:
The initial kinetic energy of the boat and its rider is

After Sam stops it, the final kinetic energy of the boat+rider is

because its final velocity is zero.
For the law of conservation of energy, the work done by Sam is the variation of kinetic energy of the system:

where the negative sign is due to the fact that the force Sam is applying goes against the direction of motion of the boat.
Answer:
Explanation:
a) 1.00 - 0.12 = 0.88
m = 1200(0.88)^t
b) t = ln(m/1200) / ln(0.88)
c) m = 1200(0.88)^10 = 334.20 g
d) t = ln(10/1200) / ln(0.88) = 37.451... = 37 s
e) t = ln(1/1200) / ln(0.88) = 55.463... = 55 s