1) 
We can solve this part by using Newton's second law:
(1)
where
F is the net force
m is the mass
a is the acceleration
There are two forces acting on the boat:
forward
backward
So the net force is

We know that the mass of the boat is
m = 1177.5 kg
So we can now use eq.(1) to find the acceleration:

2) 161.0 m
We can solve this part by using the following suvat equation:

where
s is the distance travelled
u is the initial velocity
t is the time
a is the acceleration
Here we have
u = 0 (the boat starts from rest)

Substituting t = 17.7 s, we find the distance covered:

3) 18.2 m/s
The speed of the boat can be found with the following suvat equation

where
v is the final velocity
u is the initial velocity
t is the time
a is the acceleration
In this case we have
u = 0 (the boat starts from rest)

And substituting t = 17.7 s, we find the final velocity:

And the speed is just the magnitude of the velocity, so 18.2 m/s.
The correct answer would be B. The first level contains two and the second level contains six holding a total of eight, the reason eight aren't just in one row is because only two fit in the first row.
solution:
When an uncharged conducting object brought near to a charged insulating object there is a force on the conducting object to move the electrons within it to opposite sides of the conductor. That means there is a separation of charges in the conducting object in the presence of the charged insulating object near to it but the charge on the conducting object is neutral.
Thus, the conducting object is uncharged.
There is a force of attraction between the uncharged conducting object and the insulating object when it brought near to the insulating object.
Thus, there is a force on the conducting object.
The conductor remains uncharged and a force is exerted on it.
Momentum and inertia,
Momentum=P. P=MV. M=mass and V=velocity. Mass is related to inertia so inertia=F. F=MA. A=acceleration.
.Answer:
491.4 nm
Explanation:
The distance between central and first maxima is,

And the distance between screen abnd grating is,

Now the angle can be find as,

Now the grating distance is,

Now with m=1 condition will become,

So,

Therefore the wavelength of laser light is 491.4 nm.