Since the statement of the problem is to determine if levels of acidity in sea water affect the strength of a sea snail's shell, then the best statement of hypothesis should be:
"<span> if the shells are affected by the level of acidity, then they will be weaker.</span>"
That hypothesis refers directly to the theory being questions in the problem.
“Newton's first law says that the tableware will remain motionless unless acted upon by an outside force. To set the objects on the table into motion, the horizontal force acting upon them in this case is the frictional force between them and the table cloth. “
couldn’t paraphrase i’m not too good at physics but this might help
Answer:
a). Acceleration with old model 
b). Acceleration with new model 
c). Coefficient of kinetic friction old model 
d). Coefficient of kinetic friction old model 
Explanation:
Using the Newton laws so the initial speed is zero
so:
Δ
because the ski began from the rest initial velocity is zero
Δ
a).
b).
In the horizontal direction the friction force acts on the ski is:
c).
d).
Ok so we know:
The acceleration (10ms^-2)
The initial velocity (0)
And the total time (6seconds)
Using the equation v = u + at, with v being the final velocity, u being the initial velocity, a being acceleration and t being time, we get:
v = 0 + 10x6
v = 60
So the speed after 6 seconds is 60 metres per second (6m/s)
Hope this helped
