Melanie and Lance gathered data about the effectiveness of masks
preventing disease. One of the questions they ask the experimental
subjects is their age. What type of observation is this? *

a) Two other forces that act on thee sled are the weight of the daughter and the drag force

b) The drag force slows down the sled while the weight presses it down.

We know that motion is the result of the action of unbalanced forces. From the Newton's third law, we know that if the forces that are acting on an object are balanced that the object is not going to move from its state of rest.

In this case, we are told that a  father pushes his daughter and son on a sled down a hill. The fact that the led is moving is due to the fact that there are forces that are acting on the sled.

The forces that are acting on the sled apart  from the force that was applied in pushing the sled is the drag force and the weight of the son.

The drag force would determine how fast that the sled would move because it acts in opposition to the forward force and tries to slow down the sled as it is moving. The weight of the son does press the sled downwards.

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If the question is asking for acceleration,

To find acceleration, we have to find the change in velocity over the change in time

In this case, the change of velocity is -30 km/hr and the change in time is 5 seconds

We must convert the units of sec to hours to solve this question

5 sec * 1 min/60 seconds * 1 hour/60 min = .00138889 hours

acceleration = change in velocity / change in time = -30 km/hr / .00138889 hours = -21599.999 km/hr^2 = ~-21600 km/hr^2

By applying the density formula, it can be concluded that the volume of the iron is 5.89 dL.

Density is a measurement of the mass per unit volume of an object.

ρ = m / v  where

m = mass

v = volume

An iron has:

ρ = 7.86 g/cm³ = (7.86 * 10⁻³) kg / 10⁻² dL = 7.86 * 10⁻¹ kg/dL

m = 4.63 kg

So the volume (in dL) can be calculated as follows:

Volume = mass / density

             = 4.63 / 7.86 * 10⁻¹

             = 5.89 dL

Thus the volume of the iron is 5.89 dL.

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Answer:

It conserves both energy and momentum in the collision at the same time. By design, when the balls collide the strings that hold them up are vertical (assuming balls are only swung from one side).

Explanation:

Hope This Helps!!

Uniform motion is defined as the motion in which the velocity of an object remains constant over a certain period of time. This indicates that the object moves at the same rate, in the same direction, and over the same distance.

Accelerated motion is characterized as the motion in which the velocity of an object changes with time. A few ways to differentiate between uniform motion and accelerated motion are, In uniform motion, the rate of change in velocity is zero. In accelerated motion, There is a rate of change in velocity. In uniform motion, the speed is constant, but in accelerated motion, the speed is not constant.

The change in speed is also an indicator of motion. The speed of an object undergoing accelerated motion changes from instant to instant, whereas in uniform motion, there is no change in speed. In the case of uniform motion, the displacement is proportional to time. This is not true in the case of accelerated motion because the velocity is changing with time.

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Solution1:

0.25 min = 15 secs

a = (v - \(v_{0}\)) / t

v = 0 (stops to rest), t = 15

⇒ a = -\(v_{0}\)/15

x = \(v_{0}\)t + \(\frac{1}{2}\)a\(t^{2}\)

⇒ 10.5 = \(v_{0}\) * 15 + \(\frac{1}{2}\) * \(\frac{-v0}{15}\) * 225

10.5 = \(v_{0}\) * 15 -

10.5 = \(v_{0}\) * 7.5

\(v_{0}\) = 1.4 (m/s)

⇒ a = -\(\frac{7}{75}\) (m/s^2)

Solution2:

Answer:

its b

Explanation:

cause im in  7th grade ive been asked the same question

Answer:

11. 6700L

12. 0.0000238

13. 1805

14. 3800

15. 1400

16. 0.01428

17. 0.0003585

18. 0.0415

19. 4060.0

20.0.105

Answer:

d q=3 m/s

Explanation:

im not too sure hope that helps

Answer:

20m/s

Explanation:

Given parameters:

Distance of throw = 50m

Time  = 3s

Unknown:

Average speed  = ?

Solution:

Average speed is distance divided by time;

  Average speed  = \(\frac{distance }{time}\)

Insert the parameters and solve;

  Average speed  = \(\frac{50}{3}\)   = 16.66667m/s  = 20m/s

Explanation:

Frictional force causes a lot of losses in general upkeep and wear and tear of machinery. Hence it is considered as a evil. But almost all crucial tasks cannot be carried out without the presence of friction. ... Hence it is considered as a necessary evil .

Explanation:

Frictional force causes a lot of losses in general upkeep and wear and tear of machinery. Hence it is considered as a evil. But almost all crucial tasks cannot be carried out without the presence of friction. ... Hence it is considered as a necessary evil .

Answer:

The metal is beginning to rust

Explanation:

Because when it is out side a small layer of condensation begins to form which the turns to rust as it is outside colliding with the cold air

The difference in the number of nucleons (specifically neutrons) in Argon-36 and Argon-39 leads to a difference in the balance of forces within their nuclei. This results in the stability of Argon-36 and the radioactivity of Argon-39.

In terms of the number of nucleons and the forces between them, here's why Argon-36 is stable and Argon-39 is radioactive:
1. Nucleons: Argon-36 has 18 protons and 18 neutrons, while Argon-39 has 18 protons and 21 neutrons. The difference in the number of neutrons affects the stability of the nucleus.
2. Forces: There are two main forces acting within the nucleus - the strong nuclear force, which binds the nucleons together, and the electrostatic force, which causes repulsion between protons.
3. Stability: In Argon-36, the balance between the strong nuclear force and electrostatic force is such that the nucleus remains stable. The 18 neutrons in Argon-36 are enough to overcome the electrostatic repulsion between the 18 protons, resulting in a stable nucleus.
4. Radioactivity: In Argon-39, there are 21 neutrons, which can lead to an imbalance in the forces within the nucleus. The strong nuclear force is not as effective in overcoming the electrostatic repulsion between the 18 protons. This imbalance makes the nucleus unstable and results in Argon-39 being radioactive.

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In terms of nucleons and forces between them, Argon-36 is stable while Argon-39 is radioactive due to the following reasons:

1. Nucleons: Argon-36 has 18 protons and 18 neutrons, whereas Argon-39 has 18 protons and 21 neutrons. The number of nucleons (protons and neutrons) affects the stability of the nucleus.

2. Forces: There are two main forces acting within the nucleus: the strong nuclear force, which holds the nucleons together, and the electromagnetic force, which causes repulsion between the protons.

3. Stability: In Argon-36, the balance between these forces is favorable, resulting in a stable nucleus.

The strong nuclear force is sufficiently strong to overcome the electromagnetic repulsion between the protons, creating a stable atomic nucleus.

4. Radioactivity: In Argon-39, the presence of 3 extra neutrons increases the distance between protons, reducing the strong nuclear force's ability to counteract the electromagnetic repulsion.

This imbalance makes Argon-39's nucleus unstable and more likely to undergo radioactive decay to achieve stability.

So, the number of nucleons and the forces between them determine the stability of argon isotopes, with Argon-36 being stable and Argon-39 being radioactive.

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(a) The instantaneous velocity of the car, v(t) is given by the derivative of its position with respect to time, that isv(t) = dx(t)/dt= 2t - 3t². Thus, the instantaneous velocity of the car is 2t - 3t².

(b) The instantaneous acceleration of the car, a(t) is given by the derivative of its velocity with respect to time, that is,a(t) = dv(t)/dt= d/dt(2t - 3t²) = 2 - 6tThus, the instantaneous acceleration of the car is 2 - 6t.

(c) The position of the car is maximum when the velocity is equal to zero. Thus, 2t - 3t² = 0 or t = 0 or t = 2/3. Since the velocity is increasing from negative to positive values, this means that the position of the car is maximum at t = 2/3.

(d) The displacement of the car from t = 0 to t = 2 is given by the definite integral of its velocity over that interval, that is,Δx = ∫(v(t) dt) between 0 and 2.Δx = ∫(2t - 3t² dt) between 0 and 2Δx = [t² - t³] between 0 and 2Δx = 4 - 8/3 = 4/3.

(e) The average velocity of the car from t = 0 to t = 2 is given by the ratio of the displacement to the time interval, that is,v(avg) = Δx/Δt = (4/3)/(2 - 0) = 2/3.

(f) The average acceleration of the car from t = 0 to t = 2 is given by the ratio of the change in velocity to the time interval, that is,a(avg) =\(Δv/Δt = (v(2) - v(0))/(2 - 0)a(avg) = (2(2) - 3(2)² - 2(0) + 3(0)²)/(2 - 0)a(avg) = -4/2 = -2.\)

(g) The function x(t) from t = 0 to t = 2 is shown below.

The axis on the left is the y-axis and the axis on the right is the x-axis.

The function is x(t) = t² - t³.

The maximum point on the graph is at t = 2/3 and x = 4/27.
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The proof of third equation of motion is determined as  v² = 2as + u².

The proof of third equation of motion is determined as follows;

The first equation is given as;

v = u + at

t = ( v - u ) /a

where;

The formula for the average distance traveled by an object is;

s = (v + u)/2  x  t

Expand the equation above as;

s = (v + u)/2 x  (v - u)/a

s = (v² - u²) / 2a

2as = v² - u²

v² = 2as + u², proved

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Answer:0.99 N

Explanation:

1200 N               F

||||||||||||      =   |||||||||||||||||||

3.2 m2             0.0075m2

F=0.99

To calculate the speed of the BB as it is fired from the toy gun, we can use the principle of conservation of mechanical energy. The potential energy stored in the compressed spring is converted into kinetic energy of the BB.

First, let's convert the mass of the BB to kilograms: 0.36 g = 0.36 × 10^(-3) kg.

The potential energy stored in the spring is given by the formula U = (1/2)kx^2, where k is the force constant and x is the distance the spring is compressed. Substituting the values, we have:

U = (1/2) × (1.8 × 10^4 N/m) × (0.012 m)^2 = 1.296 J

According to the conservation of mechanical energy, this potential energy will be converted into kinetic energy:

U = (1/2)mv^2, where m is the mass of the BB and v is its velocity.

Substituting the values, we can solve for v:

1.296 J = (1/2) × (0.36 × 10^(-3) kg) × v^2

Simplifying, we find:

v^2 = (2 × 1.296 J) / (0.36 × 10^(-3) kg) = 7.2 m^2/s^2

Taking the square root of both sides, we get:

v ≈ 2.68 m/s

Therefore, the speed of the BB as it is fired from the toy gun is approximately 2.68 m/s.

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Answer:

Explanation:

The collision between the 93kg fullback and the 127kg defensive tackle is an example of an inelastic collision. In an inelastic collision, the total kinetic energy of the system is not conserved as some of the energy is transformed into other forms such as heat or sound. The resulting final speed of both players would be 0m/s, indicating that they have come to a stop after the collision.

Answer:

sure

Explanation:

Answer:

uhm ok

Explanation:

Answer:

A. The particle model

Explanation:

The particle model

The substitution method is a quick and easy way to algebraically solve a set of linear equations and determine the variables' solutions.

Thus, According to what the name implies, this method entails determining the value of the x-variable in terms of the y-variable from the first equation and then substituting or replacing the value of the x-variable in the second equation.

One of the algebraic techniques for solving simultaneous linear equations is the substitution approach. It entails changing any variable's value from one equation to the other by substituting it in.

The cross multiplication method and the elimination method are the other two algebraic strategies for resolving linear equations and variables.

Thus, The substitution method is a quick and easy way to algebraically solve a set of linear equations and determine the variables' solutions.

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Answer:

The answer is C.

When Earth is positioned precisely between the Moon and Sun, Earth's shadow falls upon the surface of the Moon, dimming it and sometimes turning the lunar surface a striking red over the course of a few hours which is how a lunar eclipse happens.

When the Moon orbits Earth, the Moon moves between the Sun and Earth. When this happens, the Moon blocks the light of the Sun from reaching Earth. This causes an eclipse of the Sun, or a solar eclipse. During a solar eclipse, the Moon casts a shadow onto Earth.

Answer:

the angle of incidence equals the angle of reflection

According to the law of reflection, the angle of incidence is equal to the angle of reflection.

What is Reflection ?

Reflection is the change of direction of the wave at the interface which separates two media. it get incident on the other media and get return to the same media is called as reflection. Common examples include the reflection of light, sound and water waves.

we can see that in the dark room when we incident light on the mirror, the direction of the light changes at the point of the incidence. in the scientific language we can say that light has reflected from the surface of the mirror. in this case  angle of incidence is always equal to angle of reflection. reflection is shown in the figure.

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The momentum of the system after the Collison have been obtained as  0.20 kg-m/s south.

According to the principle of the conservation of linear momentum, we know that the momentum before collision is equal to the momentum after collision.

In this case, we can see that the two ball are moving in the opposite direction thus the velocity vectors are directed in opposite directions. We would now try to be able to obtain the momentum of the system after the Collison as;

Momentum of the ball moving south - Momentum of the ball moving north

Thus;

0.17 kg(2.8 m/s -  1.6 m/s)

Total momentum of the system =

0.20 kg-m/s south

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Answer:

D)evaluating a solution

Explanation:

In this scenario, the next logical step would be evaluating a solution. This is because Jasper and Samantha have already identified the problem/need which is that the robot needs to be able to move a 10-gram weight at least 2 meters and turn in a circle. They also designed and implemented a solution because they have already built the robot. Therefore the only step missing is to evaluate and make sure that the robot they built is able to complete the requirements.

Answer:

0.23N for the speed

at the bottom of the circle

Answer: The kinetic energy of Usain Bolt, who has a mass of 80 kg, is 4000 Joules.

Explanation:

What is the kinetic energy of Usain Bolt if he has a mass of 80 kg and is sprinting at 10 m/s?

Data:

m = mass = 80 kg

V = velocity = 10m/s

Ec = Kinetic energy = ?

To calculate the kinetic energy of Usain Bolt, we apply the following formula, substitute data and solve:

Formula for Kinetic Energy:

\(KE=.5mv^2\)

kinetic energy(measured in joules) = .5 * mass(measured in kg) * velocity(measured in m/s)^2

__________________________________________________________

Given:

\(m=80kg\)

\(v=10m/s\)

\(KE=?\)

__________________________________________________________

Finding kinetic energy:

\(KE=.5mv^2\)

\(KE=.5(80)(10)^2\)

__________________________________________________________

Answer:

\(\fbox{4000 Joules}\)

Answer:

friction

Explanation:

Her brakes will squeak and possibly slide or skid on concrete due to her brakes.

BUT it really depends on the condition of the wheels. Now it matters on the surface as well. Has the road been eroded? what has happened with her brakes? and what texture are the wheels? can seismic waves travel through them?

Answer:

thinking distance stays the same and the braking distance increases

AQA Approved.✅

Explanation:

Answer: A wave is a disturbance that transmits energy as long as it is not transmitting matter?