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4 years ago

If the net external force acting on a system is zero , then the total momentum of the system is zero

2 answers:

8 0

If net external force acting on the system is zero, momentum is conserved. That means, initial and final momentum are same → total momentum of the system is zero.

antoniya [11.8K]4 years ago

8 0

Answer: FALSE

Explanation: Momentum is the product of the mass of an object and the velocity of that object,momentum is a vector quantity which means it has a Magnitude (distance covered) and Direction.

Force is the product of the mass of an object and its acceleration,Force can also be described as the weight of an object after the force of gravity acts on its mass.

If the net force acting on an object is zero it does not mean that the momentum of that system is zero, because momentum does not solely depends on forces,it has to do with the MASS of the object and the VELOCITY of the object.

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the gravitational force between two objects is 1600 and what will be the gravitational force between the objects if the distance

Xelga [282]

I believe this is what you have to do:

The force between a mass M and a point mass m is represented by

$F = G\frac{Mm}{r^{2} }$

So lets compare it to the original force before it doubles, it would just be the exact formula so lets call that F₁

So F₁ = G(Mm/r^2)

Now the distance has doubled so lets account for this in F₂:

F₂ = G(Mm/(2r)^2)

Now square the 2 that gives you four and we can pull that out in front to give

F₂ = $\frac{1}{4}$ G(Mm/r^2)

Now we can replace G(Mm/r^2) with F₁ as that is the value of the force before alterations

now we see that:

F₂ = $\frac{1}{4}$ F₁

So the second force will be 0.25 (1/4) x 1600 or 400 N.

6 0

3 years ago

You apply a horizontal force of 25N to push a shopping cart across the parking lot at a constant velocity. a) what is the net fo

AlekseyPX

(a) The net force on the shopping cart is zero.

(b) The the force of friction on the shopping cart is 25 N.

<h3>Net force on the shopping cart</h3>

The net force on the shopping cart is calculated as follows;

F(net) = F - Ff

where;

F is the applied force
Ff is the frictional force

ma = F - Ff

where;

a is acceleration of the cart
m is mass of the cart

at a constant velocity, a = 0

0 = F - Ff

F(net) = 0

F = Ff = 25 N

Net force is zero, and frictional force is equal to applied force.

<h3>On wet surface</h3>

Coefficient of kinetic friction of solid surface is greater than that of wet surface.

Since frictional force limit motion, when the frictional force is smaller, the object tends to move faster.

Thus, the cart will move faster on a wet surface due to decrease in friction.

Learn more about frictional force here: brainly.com/question/24386803

#SPJ1

4 0

2 years ago

How should the student change the circuit to give negative values for current and

natulia [17]

Answer:

changing the polarity or direction of the battery changes the sign of the voltage and the current

Explanation:

The sign of current and voltage are due to established conventions.

The way that a DC circuit with negative current values is by changing the polarity of the power source or by inverting the battery, this creates that the electrons move in the opposite direction

Changing the battery also changes the direction of the power difference, since the potential from positive to negative, in most cases negative is assigned a potential of zero volts

In summary, changing the polarity or direction of the battery changes the sign of the voltage and the current

3 0

3 years ago

Identifying What are five things

g100num [7]

Answer:

1. Naturally occuring

2. Solid

3. Inorganic

4. Crystalline

5. Specific Chemical Compostion

Explanation:

Minerals are inorganic, crystalline solids that occur during biogeochemical processes in nature like in cooled lava or evaporated sea water. Minerals are not rocks, but are actually the components that make up rocks. Though they vary in color and shape, each mineral has a distinct chemical composition.

1. Minerals are formed by natural geological processes. Most minerals form from molten lava, sea evaporation or hot liquids in caves or cracks. Laboratory-generated minerals like synthetic gems made for commercial purposes are not considered actual minerals.

2. Though minerals vary in shape, color, luster (the way a mineral reflects light) and hardness, all minerals are a solid at a given temperature. If a substance is not in its solid state, it is not currently a mineral. For example, ice is a mineral, but liquid water is not. The Mohr scale, rates a minerals hardness from one to 10, 10 being the hardest. Diamond is the hardest mineral. Talc is a very soft mineral with a Mohr rating of one.

3. Minerals are wholly inanimate, inorganic compounds. But there are exceptions to this qualifier. There are rare organic substances with definitive chemical compositions that are labeled as “organic minerals." The most famous of this oxymoronic exception is whewellite. Whewellite is a component of kidney stones and coal deposits.

4. Most minerals will grow into a crystal shape, space permitting. Mineral deposits are often small because there is usually a variety of minerals in the same vicinity competing for the same room to grow. A mineral’s crystalline structure determines its hardness, cleavage (how it breaks) and color. There are six different crystal shapes: cubic, tetragonal, orthohombic, hexagonal, monoclinic and triclinic.

5. A mineral is defined by its chemical composition. A rock, on the other hand, does not have a specific chemical composition because it is a composite of a variety of minerals. Minerals are classified based on their anionic group. The major mineral groups are native elements, sulfides, sulfosalts, oxides and hydroxides, halides, carbonates, nitrates, borates, sulfates, phosphates and silicates. Silica is abundant in the Earth’s crust, so silicates are the most common group of mineral.

4 0

2 years ago

Determine the direction of the force that will act on the charge in each of the following situations. A negative charge moving t

wlad13 [49]

Answer:

a) DOWN direction, b) directed INTO THE SCREEN, c) F = 0

Explanation:

The direction of the force is

for electric force

F = q E

where we assume a positive test charge, for which the force has the direction of the electric field.

For a magnetic field

in this case the direction of the force is given by the right hand rule.

For a positive test charge, the thumb points in the direction of velocity, the other fingers extended in the direction of the magnetic field, and the palm gives the direction of force for a positive charge.

F = q v x B

Let us apply these considerations to our case.

a) negative charge moving to the left

in a magnetic field points away from the screen

In this case the thumb goes to the left, the fingers extended outwards and the palm points upwards, but since the charge is negative the force has a DOWN direction.

b) negative charge moves to the left

in electric field it points off the screen.

The outside is in the direction of the electric field and since the charge is negative, the force is directed INTO THE SCREEN

c) positive charge moves down

in magnetic field points up

in this case the velocity and the field have the same direction so the vector product of them is zero

F = q v B sin 0

F = 0

6 0

3 years ago