Answer:
The vector sum of all forces acting on it is zero, its at equilibrium.
Explanation:
The bag of marbles hanging on a spring scale applies its weight downwards, which was counterbalanced by the reaction from the spring scale (obeying the Newton's third law of motion). And since no external forces are applied to the system, thus the equilibrium of the system.
If the weight of the bag is greater than the reaction from the spring scale, the scale breaks and the system would not be balanced.
PART A)
Here we know that
potential difference across the wire is

resistance of wire is

now by ohm's law



Part b)
Power rating is defined as rate of electrical energy
it is defined as

now we have


<span>A. crest, crest
hope im right!(: </span>
Answer:
w = 73 N
Explanation:
Since the box is held by the ropes it means that the resulting tension is equal to the weight of the box
T_res = w
Now, the resulting tension is a combination of the tension of each rope.
Since we want to find the vertical component we must multiply by the cosine of 30 degrees the value of T
T_res = T*cos(30) + T*cos(30)
T_res = 2*(42 N)*(0.866)
T_res = 72.746 N
T_res = w = 72.746 N
Answer:
The second engine with no cars will accelerate more.
Explanation:
Since the engines are identical so they hacve the same mass. The first engine has 10 cars attached which adds more mass to it whereas second engine has no cars attached.
Therefore second engine is lighter in mass than the first one.
<u>We know from the Newton's second law of motion:</u>


Now, according to question both the engines exert same force for moving.
We see that :

So more is the mass, lesser is the acceleration, hence the second engine with no cars will accelerate more.