This is also for a test

The forces : = 90 N, moving right, unbalanced forces

Given

The forces acting on an object

Required

The net force

Solution

Net force : the sum of all forces acting on an object

We agree that the move up and to the right is a positive sign, while down and to the left is a negative sign.

If we look at the net force, the direction of the forces are to the right (both forces, 60 N and 30 N)⇒horizontal motion

the same direction, add the forces  

the opposite direction, subtract the forces  

Unbalanced forces, the object will move

The object will not move if forces are balanced (net force = 0)  

So the net force :

= 60 N + 30 N

= 90 N to the right

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

24

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.