All categories

3 years ago

Which of the following is an incorrect statement of one of newtons laws of motion?

Physics

1 answer:

weqwewe [10]3 years ago

5 0

Explanation:

The newton's laws of motion are:

First law:

"A body will remain in its state of rest or of uniform motion along a path unless it is acted upon by an external force. ".

This is popularly called the law of inertia.

Second law:

"the acceleration of a body is produced by a net force that is inversely proportional to the mass of the body".

Third law:

"action and reaction forces are equal and opposite in direction".

learn more:

Newton's laws brainly.com/question/11411375

#learnwithBrainly

You might be interested in

A large balloon of mass 210 kg is filled with helium gas until its volume is 329 m3. Assume the density of air is 1.29 kg/m3 and

Nastasia [14]

(a) See figure in attachment (please note that the image should be rotated by 90 degrees clockwise)

There are only two forces acting on the balloon, if we neglect air resistance:

- The weight of the balloon, labelled with W, whose magnitude is

$W=mg$

where m is the mass of the balloon+the helium gas inside and g is the acceleration due to gravity, and whose direction is downward

- The Buoyant force, labelled with B, whose magnitude is

$B=\rho_a V g$

where $\rho_a$ is the air density, V is the volume of the balloon and g the acceleration due to gravity, and where the direction is upward

(b) 4159 N

The buoyant force is given by

$B=\rho_a V g$

where $\rho_a$ is the air density, V is the volume of the balloon and g the acceleration due to gravity.

In this case we have

$\rho_a = 1.29 kg/m^3$ is the air density

$V=329 m^3$ is the volume of the balloon

g = 9.8 m/s^2 is the acceleration due to gravity

So the buoyant force is

$B=(1.29 kg/m^3)(329 m^3)(9.8 m/s^2)=4159 N$

(c) 1524 N

The mass of the helium gas inside the balloon is

$m_h=\rho_h V=(0.179 kg/m^3)(329 m^3)=59 kg$

where $\rho_h$ is the helium density; so we the total mass of the balloon+helium gas inside is

$m=m_h+m_b=59 kg+210 kg=269 kg$

So now we can find the weight of the balloon:

$W=mg=(269 kg)(9.8 m/s^2)=2635 N$

And so, the net force on the balloon is

$F=B-W=4159 N-2635 N=1524 N$

(d) The balloon will rise

Explanation: we said that there are only two forces acting on the balloon: the buoyant force, upward, and the weight, downward. Since the magnitude of the buoyant force is larger than the magnitude of the weigth, this means that the net force on the balloon points upward, so according to Newton's second law, the balloon will have an acceleration pointing upward, so it will rise.

(e) 155 kg

The maximum additional mass that the balloon can support in equilibrium can be found by requiring that the buoyant force is equal to the new weight of the balloon:

$W'=(m'+m)g=B$

where m' is the additional mass. Re-arranging the equation for m', we find

$m'=\frac{B}{g}-m=\frac{4159 N}{9.8 m/s^2}-269 kg=155 kg$

(f) The balloon and its load will accelerate upward.

If the mass of the load is less than the value calculated in the previous part (155 kg), the balloon will accelerate upward, because the buoyant force will still be larger than the weight of the balloon, so the net force will still be pointing upward.

(g) The decrease in air density as the altitude increases

As the balloon rises and goes higher, the density of the air in the atmosphere decreases. As a result, the buoyant force that pushes the balloon upward will decrease, according to the formula

$B=\rho_a V g$

So, at a certain altitude h, the buoyant force will be no longer greater than the weight of the balloon, therefore the net force will become zero and the balloon will no longer rise.

4 0

3 years ago

Which of the following answers is NOT an example of repetition?

Step2247 [10]

Answer:

the first one.

Explanation: I don't exactly but, I know the other three sounds more like repetition! Hope this helps

5 0

3 years ago

. A solenoid coil consists of a single layer of 250 circular turns of wire with each turn having a 0.02m radius. The axial lengt

Vinil7 [7]

Answer:

a) L = 3.29 10⁻⁴ H, b)U = 5.33 10⁻² J

Explanation:

a) The inductance is a solenoid this given carrier

L = $\frac{N \ \phi_B }{I}$

The magnetic field inside the solenoid is

B = μ₀ $\frac{N}{l} i$

hence the magnetic flux

Ф_B = B. A = μ₀ $\frac{N \ A}{l \ i}$

we substitute in the expression of inductance

L = N² μ₀ A /l

let's find the area of each turn

A = π r²

A = π 0.02²

A = 1.2566 10⁻³ m²

let's calculate

L = 250² 4π 10⁻⁷ 1.2566 10⁻² / 0.3

L = 3.29 10⁻⁴ H

b) The stored energy is

U = ½ L i²

let's calculate

U = ½ 3.29 10⁻⁴ 18²

U = 5.33 10⁻² J

5 0

3 years ago

suppose that 273 g of one of the substances listed above displaces 26 mL of water. What is the substance?

guajiro [1.7K]

<span>The unknown substance is silver. I don't see a list of available substances, but let's see if there's something reasonable available that will match. First, let's calculate the density of the unknown substance. Density is mass per volume, so 273 g / 26 mL = 10.5 g/mL Looking up a list of elements sorted by density, I see the following: 10.07 Actinium 10.22 Molybdenum 10.5 Silver 11.35 Lead And silver at 10.5 g/ml is a very nice match for the unknown substances' density of 10.5 g/ml.</span>

6 0

4 years ago

Read 2 more answers

Can someone help me on no. 6

liq [111]

Efficiency = (energy that does the job) / (total energy used)

= (45 J) / (120J)

I think you can handle the division.

8 0

3 years ago