Answer:
+300N-130N=170N
Explanation:
because two forces in opposite direction one take +and the other takes -
10. A safe place to use the trebuchet would be away from other buildings and people. A good example of a place would be a large field with no nearby structures.
14. Many factors need to be kept consistent throughout the experiment. One example of a variable that would need to be consistent is the weight and size of the projectile.
15. It is important to do many trials so that you can make sure that the results of each trial are nearly the same. If they are all vastly different, then it means that something has gone wrong.
Sorry I was only able to answer a few questions, but I hope these few answers help! :)
Answer:
a.After 
second Mr Comer's speed 
b.Distance travelled by Mr.Comer in seconds 
Explanation:
a. Lets recall our first equation of motion 
Now we know that 
, 
and
Plugging the values we have.
Then Mr.Comer's speed after sec 
b.
Lets find the distance and recall our third equation of motion.
So 
distance covered.
Dividing both sides with 2a we have.
Plugging the values.
So Mr.Comer will travel a distance of .
Answer:
A fair test.
Explanation:
Hi, a fair test is used to do scientifically valuable experiments, is a controlled investigation to answer a scientific question.
In a fair test two or more things are compared.
It consists in changing only one factor (the one bieng tested) and keeping all the other conditions the same during an experiment.
The factor is called a variable.
At position of maximum height we know that the vertical component of its velocity will become zero
so the object will have only horizontal component of velocity
so at that instant the motion of object is along x direction
while if we check the acceleration of object then it is due to gravity
so the acceleration of object is vertically downwards
so it is along y axis
so here these two physical quantities are perpendicular to each other
so correct answer would be
<em>C)At the maximum height, the velocity and acceleration vectors are perpendicular to each other. </em>
