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3 years ago

Which statements best describe magnets? Check all that apply.

Physics

2 answers:

lesya692 [45]3 years ago

6 0

Answer:

1,2,4,5 on edge

Explanation:

bearhunter [10]3 years ago

3 0

Answer:

Following are the conditions that describe magnets:

1. Magnets act at a distance. (Yes, Magnets act at a distance. Touching the material is not a requirement)

2. Magnets have two poles. (Even if you break a magnet, each piece will have two poles)

4. Magnets have a magnetic field around them. (The magnetic field weakens as the distance increases)

5. Materials that are attracted to a magnet contain iron, cobalt, or nickel.

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Can someone help with numbers 5-8??

Keith_Richards [23]

5. Left

Explanation: centripetal acceleration is the acceleration that acts on an object which is moving by circular motion. The direction of the centripetal acceleration is always towards the centre of the circular trajectory: that means that for a car following a bend, the direction of the centripetal acceleration is towards the centre of the bend, and so it is towards the left if the bend is towards the left, and towards the right if the bend is towards the right.

In this example, the road in this bend is going to the left, so centripetal acceleration is toward the left as well.

6. Greater

Explanation: Inertia represents the tendency of an object at staying in motion if it is moving, and at staying at rest if the object is at rest. We can also see inertia as a measure of "how difficult it is" to put an object in motion. Due to this definition, we can also notice that inertia is directly proportional to the mass of the object: the greater the mass, the greater the inertia, because it is more difficult to put the object in motion.

So, in this example, the greater the boulder's mass, the greater inertia it has.

7. Direction

Explanation: displacement is a vector quantity that represents the difference in position between an object and a starting point. Because it is a vector, displacement consists of two elements:

- A magnitude, which is equal to the object's distance from the starting point

- A direction, again compared to the starting point

So, displacement depends on the object's distance and direction from the starting point.

8. Negative

Explanation: acceleration is defined as the rate of change of velocity; in formula:

$a=\frac{v-u}{t}$

where v is the final velocity, u the initial velocity, and t the time taken to accelerate from u to v. From the formula, we see that:

- When the final velocity (v) is greater than the initial velocity (u), acceleration is positive

- When the final velocity (v) is smaller than the initial velocity (u), acceleration is negative

In this problem, we have a car slowing down: it means that the final velocity is smaller than the initial velocity, so in this case acceleration is negative.

7 0

3 years ago

In 1909 Robert Millikan was the first to find the charge of an electron in his now-famous oil drop experiment. In the experiment

mrs_skeptik [129]

Answer:

$1.49\cdot 10^{-17}C$

Explanation:

The oil drop remains stationary when the electric force on it and the gravitational force are balanced, so we have:

$F_E = F_G\\qE = mg$

where

q is the charge of the oil drop

E is the electric field strength

m is the mass of the drop

g is the acceleration due to gravity

here we have

$E=1\cdot 10^6 N/C$

$m=1.51837\cdot 10^{-12} kg$

$g=9.8 m/s^2$

So the charge of the drop is

$q=\frac{mg}{E}=\frac{(1.51837\cdot 10^{-12} kg)(9.8 m/s^2)}{1\cdot 10^6 N/C}=1.49\cdot 10^{-17}C$

8 0

3 years ago

This diagram shows about question 3 In this diagram, the forces on the runner and on the ground are equal. Why does the runner m

Dovator [93]

According to newton's third law: every action has an equal and opposite reaction, so yes the ground does move backwards. You have 4 forces acting on you at any given time: pushing force, friction force, gravity, and normal force. you push against something to propel forward, you have to overcome gravity and friction, and normal force keeps things upright to prevent them from falling into each other.

<span>If everything is motionless at every instant, and time is entirely composed of instants, then motion is impossible, so it must be an illusion.
</span>

if you really want things to get confusing you can read up on zeno's dichotomy paradox stating that there is infinate amount of times you can divide something such as a distance traveled over time and you will stil

7 0

4 years ago

1. This heating system maintains room temperature at or near a particular value, known as the .

stiv31 [10]

Answer:

Explanation:

1. This heating system maintains room temperature at or near a particular value, known as the set point.

A temperature setpoint is the level at which the body attempts to maintain its temperature. When the setpoint is raised, the result is a fever.

2. You open the window, and a blast of icy air enters the room. The temperature drops to 17 degrees Celsius, which acts as a STIMULUS to the heating system.

3. The thermostat is a SENSOR that detects the stimulus and triggers a response.

Thermostat is use to turn off or on a switch, when the temperature is high or low

4. The heater turns on, and the temperature in the room INCREASE until it returns to the original setting.

This is the work of the thermostat above, when the temperature of the room is below a certain temperature the thermostat triggered the switch and keep increasing the temperature of the room until normal setting.

5. The response of the heating system reduces the stimulus. This is an example of NEGATIVE feedback.

Body temperature is regulated by negative feedback. The stimulus is when the body temperature exceeds 37 degrees Celsius, the sensors are the nerve cells with endings in the skin and brain, the control is the temperature regulatory center in the brain, and the effector is the sweat glands throughout the body.

6. The way this heating system maintains a stable room temperature is similar to the way an animal's body controls many aspects of its internal environment. The maintenance of a relatively constant internal environment is known as HOMEOSTASIS.

Humans rely on homeostasis to keep their core temperature hovering around 98.6 degrees Fahrenheit, so that their bodies can maintain proper function. Homeostasis is the ability to maintain a relatively stable internal state that persists despite changes in the world outside.

5 0

4 years ago

his is a multi-part question. Once an answer is submitted, you will be unable to return to this part. Air enters a nozzle steadi

zepelin [54]

Answer:

his is a multi-part question. Once an answer is submitted, you will be unable to return to this part. Air enters a nozzle steadily at 2.21 kg/m3 and 40 m/s and leaves at 0.762 kg/m3 and 192 m/s. The inlet area of the nozzle is 90 cm2.

determine (a) the mass flow rate through the nozzle, and (b) the exit area of the nozzle.

a)0.7956kg/s

b)5.437 × 10⁻³m²

Explanation:

The concepts related to the change of mass flow for both entry and exit is applied

The general formula is defined by

$\dot{m}=\rho A V$

Where,

$\dot{m} = mass flow rate\\\rho = Density\\V = Velocity$

values are divided by inlet(1) and outlet(2) by

$\rho_1 = 2.21kg/m^3V_1 = 40m/s$

$A_1 = 90*10^{-4}m^2\\\rho_2 = 0.762kg/m^3\\V_2 = 192m/s$

PART A) Applying the flow equation

$\dot{m} = \rho_1 A_1 V_1\\\dot{m} = (2.21)(90*10^{-4})(40)\\\dot{m} = 0.7956kg/s$

PART B) For the exit area we need to arrange the equation in function of Area, that is

$A_2 = \frac{\dot{m}}{\rho_2 V_2}\\A_2 = \frac{0.7956}{(0.762)(192)}\\A_2 = 5.437*10^{-3}m^2$

7 0

3 years ago