Answer:
i think its false
explanation
A 2.1 x 10^3 kg car starts from rest at the top of a driveway that is sloped at an angle of 20 with the horizontal. An average friction force of 4.0 x 10^3 N impedes the car's motion so that the car's speed at the bottom of the driveway is 3.8 m/s. What is the length of the driveway?
Answer:
The length of the driveway is 4.98 m
Explanation:
Given that m = mass of car = 2.1 × 10³ kg, d = length of driveway, f = frictional force = 4.0 × 10³ N, v = velocity of car at bottom of driveway = 3.8 m/s, u = speed of car at top of driveway = 0 m/s (since it starts at rest) and θ = slope of driveway = 20°
The component of the weight of the car along the driveway minus the frictional force = the net force. So,
mgsinθ - f = ma where a = acceleration of the car
a = gsinθ - f/m
substituting the variables, we have
a = 9.8 m/s²sin20° - 4.0 × 10³ N/2.1 × 10³ kg
a = 3.352 m/s² - 1.905 m/s²
a = 1.447 m/s²
a ≅ 1.45 m/s²
Using v² = u² + 2ad, we find the length of the driveway, d. So,
d = (v² - u²)/2a
Substituting the values of the variables, we have
d = (v² - u²)/2a
d = ((3.8 m/s)² - (0 m/s)²)/(2 × 1.45 m/s²)
d = 14.44 m²/s² ÷ 2.9 m/s²
d = 4.98 m
So, the length of the driveway is 4.98 m
The length of the driveway on which the car is moving is 5 m.
The given parameters;
mass of the car, m = 2,100 kgangle of inclination, θ = 20⁰frictional force, F = 4000 Nspeed of the car, v = 3.8 m/s.The net horizontal force on the car is calculated as follows;
[tex]mgsin \theta - F = ma\\\\a = \frac{mgsin \theta - F}{m} \\\\a = \frac{(2100 \times 9.8 \times sin \ 20) - 4000}{2100}\\\\a = 1.45 \ m/s^2[/tex]
The length of the driveway is calculated as follows;
[tex]v^2 = u^2 + 2as\\\\s = \frac{v^2 - u^2 }{2a} \\\\s = \frac{3.8^2 - 0}{2\times 1.45} \\\\s = 5 \ m[/tex]
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Which is an example of
kinetic energy?
A. An apple falling from a tree
B. A book sitting on a table
C. A plate of hot food
D. A parked car
Answer:
A. an apple falling from a tree
Explanation:
A runner is jogging in a straight line at a steady vr= 7.3 km/hr. When the runner is L= 2.1 km from the finish line, a bird begins flying straight from the runner to the finish line at vb= 29.2 km/hr (4 times as fast as the runner). When the bird reaches the finish line, it turns around and flies directly back to the runner After this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. The bird repeats the back and forth trips until the runner reaches the finish line. How far does the bird travel from the beginning (including the distance traveled to the first encounter
Answer:
Explanation:
Time taken by jogger to travel the distance to finishing line = 2.1 / 7.3
= .28767 hr
Bird will keep flying for this time period
distance covered by bird = speed x time
= 29.2 x .28767 km
= 8.4 km .
please help 25 points!
Select the following statements that apply to velocity.
a. Velocity is a vector quantity.
b.Velocity is a scalar quantity.
c. Velocity is the same thing as speed.
d.Velocity is speed with net force.
e. Velocity is speed with direction.
a) Velocity is a vector quantity
e) Velocity is a speed with direction
=================================================
Explanation:
If we know the velocity of an object, then we know how fast it's going (speed) and where it's going (direction). It is a vector because the direction of the vector determines the direction, and the length of the vector (aka magnitude) determines the speed. So in a sense we've built in two facts of data into one visual.
An example of velocity: 10 miles per hour north. Here we have the speed of 10 mph and the direction north.
-------------------
Extra info:
Choice B contradicts choice A, so we can cross choice B off the list.Choice C is false because speed is a scalar, or single quantity, and not a vector. As mentioned earlier, speed is a part of velocity, but they aren't the same exact thing. Choice D is false because the velocity does not account for net force. We don't have any force information built into the velocity.a. Velocity is a vector quantity.
b.Velocity is a scalar quantity. NOT
c. Velocity is the same thing as speed. NOT
d.Velocity is speed with net force. NOT
e. Velocity is speed with direction.
Consider a double Atwood machine constructed as follows: A mass 4m is suspended from a string that passes over a massless pulley on frictionless bearings. The other end of this string supports a second similar pulley, over which passes a second string supporting a mass of 3m at one end and m at the other. Using two suitable generalized coordinates, set up the Lagrangian and use the Lagrange equations to find the acceleration of the mass 4m when the system is released. Explain why the top pulley rotates even though it carries equal weights on each side.
Why doesn’t the sugar cross the cell membrane and diffuse the way the way does?
Answer:
Although glucose can be more concentrated outside of a cell, it cannot cross the lipid bilayer via simple diffusion because it is both large and polar. To resolve this, a specialized carrier protein called theglucose transporter will transferglucose molecules into the cell to facilitate its inward diffusion.
Explanation:
Please mark as brainlist answers.
Mamie Clark was a psychologist who is known for her research on __________. A. intellectual and developmental disabilities and gifted children B. racism and its adverse effects on child development C. identity development among Asians living in the US D. academic development of children in desegregated schools
Answer:
B. racism and its adverse effects on child development
Explanation:
Dr. Mamie Clark studied the effects of segregation and racism on the self-esteem of black children.
According to Clark in O'Connell & Russo, 2001, p. 271; "To separate them from others of similar age and qualifications solely because of their race generates a feeling of inferiority as to their status in the community that may affect their hearts and minds in a way unlikely ever to be undone...."
One of her works titled "The Development of Consciousness of Self and the Emergence of Racial Identification in Negro Preschool Children" investigated the early level of conscious racial identity in black preschool children.
Answer:
B
Explanation:
cuz its B
Which of these causes summer in the northern hemisphere?
The Sun is closer to Earth during the summer.
The northern hemisphere receives more direct sunlight during the summer.
Earth's northern axis is tilted away from the Sun during the summer.
The North Pole is tilted away from the Sun during the summer.
Answer:
The northern hemisphere receives more direct sunlight during the summer.
PLEASE HELP
Which object has the least average speed?
A. object A
B. object B
C. object C
D. object D
Answer:
D
Explanation:
I could be wrong, But I'm pretty sure it's D
What is a good question for a Science Fair (7th grade advanced) also im an online student so nothing really physical something that can really explain thru pictures. I just want suggestions thank you.
Two particles are separated by 0.38 m and have charges of -6.25 x 10-°C
and 2.91 x 10-°C. Use Coulomb's law to predict the force between the
particles if the distance is cut in half. The equation for Coulomb's law is
Fe = kqu92, and the constant, k, equals 9.00 x 109 Nm2/C2
A. 1.13 x 10-6N
B. 4.53 x 10-6N
C. -1.13 x 10-6N
D. -4.53 x 10-6N
Answer:
-4.53 X 10-6N
Explanation:
apex
Jared would describe a square as having four equal sides and four right angles. This is Jared’s __________ of a square. A. model B. hierarchy C. feature D. concept Please select the best answer from the choices provided A B C D
Answer:
d
Explanation:
Jared would describe a square as having four equal sides and four right angles. This is Jared’s conceps of a square.
What are squares?A square has four equal sides, four vertices, and is a closed, two-dimensional object. It has parallel sides on either side. A square is also equivalent to a rectangle with equal length and width.
Many objects can be found in your surroundings that have a square shape. The chessboard, craft sheets, bread slice, picture frame, pizza box, wall clock, etc. are typical instances of this shape.
A square is a two-dimensional closed shape with 4 equal sides and 4 vertices. Its opposite sides are parallel to each other. We can also think of a square as a rectangle with equal length and breadth.
Therefore, Jared would describe a square as having four equal sides and four right angles. This is Jared’s conceps of a square.
To learn more about square, refer to the link:
https://brainly.com/question/14198272
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PLEASE HELP!!!
If the potential difference across a 30.0-ohm resistor is 10.0 volts, what is the current through the resistor?
Megan is standing on a ladder picking apples in her grandfathers orchard. As she pulls each Apple off the tree, tosses it into a basket that sits on the ground 3.0m below at a horizontal distance of 2.0m from Megan. How fast must Megan throw the apples (horizontally) in order for them to land in the basket
Answer:
2 meters per second
Explanation:
The air inside a room is at a temperature of 35°C and has a mixing ratio of 7.6 g/kg. a) What is the relative humidity? % b) What is the dew point? °C c) If the room temperature decreases by 5°C per hour, how many hours will it take for the air to reach saturation? hours d) After reaching saturation, if the temperature of the room continues to decrease for one more hour, approximately how many grams of water vapor (per kg of air) will ahve had to condense out of the air to maintain a relative humidity of 100%? g/kg
Answer:
(a). The relative humidity is 20.57%
(b). The dew point is 79.114°F
(c). It take for the air to reach saturation is 17 hours.
(d). The water is 7.6g/kg.
Explanation:
Given that,
Temperature = 35°
Mixing ratio = 7.6 g/kg
(a). We need to calculate the relative humidity
Using formula of relative humidity
[tex]relative humidity=\dfrac{mixing\ ratio}{36}\times100[/tex]
[tex]relative humidity=\dfrac{7.6}{36.94}\times100[/tex]
[tex]relative humidity=20.57\%[/tex]
(b). We need to calculate the dew point
Using formula of dew point
[tex]dew\ point=T^{\circ}F-\dfrac{(100-relative\ humidity)}{5}[/tex]
Put the value into the formula
[tex]dew\ point=95-\dfrac{100-20.57}{5}[/tex]
[tex]dew\ point=79.114^{\circ}F[/tex]
(c). If the room temperature decreases by 5°C per hour
We need to calculate the time
Using formula of time
[tex]t=\dfrac{T_{a}-increase\ temperature}{5}[/tex]
Put the value into the formula
[tex]t=\dfrac{95-10}{5}[/tex]
[tex]t=17\ hours[/tex]
(d). If the temperature of the room continues to decrease for one more hour,
We need to calculate the how many grams of water vapor
Using given data
The water of 7.6g/kg vapour will have to condense out of air for the maintain relative humidity at 100%
Hence, (a). The relative humidity is 20.57%
(b). The dew point is 79.114°F
(c). It take for the air to reach saturation is 17 hours.
(d). The water is 7.6g/kg.
Answer:
temp: 35° c (95°f)
MR:7.6
SMR: 36.5
RH: 21% (20.82)
Dew Point: 10° C
5°c per hour: 5 hours for the 35°c air temp to reach the 10°c dew point
1 more hour: Temperature will decrease to 5°c, half the water molecules dewpoint "size" I view it as, and 3.8g/kg of water vapour has condensed out
so
1. 21%
2. 10° C
3. 5 hours
4. 3.8g/kg
What if there's an asteroid with more mass coming towards earth
The modern periodic table is organized by:
atomic number
atomic mass
chemical name
chemical symbol
Please help i will Mark it Brainly
Answer:
2nd one :)
Explanation:
Answer: the second one
Explanation:
Is a cookie crumbling or in other words breaking a cookie a physical change?
Answer:
Yes it is a physical change
Explanation:
The cookie is still a cookie even when it has been broken apart, so it cannot be a chemical change. The cookie only changed physically.
Miguel added 150 grams of baking soda to a liter of water at 20 °C. No matter how long he keeps stirring the solution, he can’t get all of the baking soda to dissolve. Explain why.
Answer:
See the answer below
Explanation:
This is because, at 20 °C, the solution has become saturated with the baking soda.
The solubility of a substance is the maximum amount of that substance that will dissolve in a particular solvent at a given temperature. The solubility of a substance generally increases with an increase in temperature.
At 20 °C temperature, the maximum amount of baking soda that can dissolve in a liter of water has been exceeded by Miguel. Hence, no matter how hard he tries to stir the solution, the excess baking soda will not dissolve.
The reason he can’t get all of the baking soda to dissolve is; because at 20 °C, the solution has become saturated with the baking soda.
What is a saturated solution?For us to say a substance is soluble, it means that the maximum amount of that substance will dissolve in a particular solvent at a given temperature. Thus, the solubility of a substance is said increase with a corresponding increase in temperature.
From the question, at 20 °C temperature, miguel has exceeded the maximum amount of baking soda that can dissolve in a liter of water. Therefore, no matter how hard he tries to stir the solution, it will not dissolve due to the excess soda.
Read more about saturated solution at; https://brainly.com/question/4529762
In which scenario will the two objects have the greatest gravitational force
between them?
A. Mass of object 1 = 15 kg
Mass of object 2 = 12 kg
Distance between objects = 0.5 m
B. Mass of object 1 = 15 kg
Mass of object 2 = 12 kg
Distance between objects = 1.5 m
C. Mass of object 1 = 12 kg
Mass of object 2 = 12 kg
Distance between objects = 0.5 m
h
O D. Mass of object 1 = 12 kg
Mass of object 2 = 12 kg
Distance between objects = 1.5 m
Ansewer
A
Explanation:
Answer : B
Explanation: Right answer trust me!
Which statement best expresses Newton's second law of motion?
A: The acceleration of an object depends on the balance between the net applied forces.
B: The acceleration of an object depends on the balance between friction and gravity.
C: The acceleration of an object depends on the object's mass and the net applied force.
D: The acceleration of an object depends on the object's mass and its velocity.
Answer:
option C
since F=ma
the acceleration of an object depends on the object's mass and the net applied force
What acceleration will all objects experience during their flights through the air (on Earth)?
Answer:
d
Explanation:
Answer:
9.8 m/s/s
Explanation:
As such, all objects free fall at the same rate regardless of their mass. Because the 9.8 N/kg gravitational field at Earth's surface causes a 9.8 m/s/s acceleration of any object placed there, we often call this ratio the acceleration of gravity
The car is moving forward with 10 N of force but the friction of
the road applies 8 N of force in the opposite direction. What
are the combined forces acting on the car?
two same size anvils are dropped from different heights (one higher than the other) . Assume both anvils are made of the same material (iron) and there is no air resistance. Which anvil hits the ground first
Answer:
The anvil that was held the lowest.
Explanation:
Assuming they were dropped at the same time, the anvil that was held at the lowest point, will hit the ground first.
PLEASE HELP!!!! ILL MARK BRAINLYEST!!
A change in the size or shape of a substance is a _________ change
A. chemical
B. physical
C. material
D. nuclear
Technician A says that leather shoes offer more protection than canvas shoes. Technician B says that steel toed boots are essential to protecting your feet from injury. Which technician is correct?
A) Technician A only B) Technician B only
C) Both technicians A and B D) Neither technician A nor B
Answer: Both technicians A and B
Explanation:
Based on the scenario in the question, it should be noted that leather shoes offer more protection than canvas shoes and that steel toed boots are essential to protecting your feet from injury.
Leather shoes are more durable and offer better protection than canvas. The strength of the material that they're made from can help in offering extra protection which is necessary in an environment where there's possibility of accidents involving falling objects.
Also, for the people who work in a work environment with many heavy machines and equipments, it is vital to it on protective steel toed boots in order to prevent the workers from feet related injuries.
Pretest: Waves
18
Select the correct answer.
Which type of wall would make the best soundproofing for room?
OA.
1.0 centimeter thick glass
OB.
two layers of 0.5 centimeter thick glass with 0.5 centimeters of air between them
OC.
two layers of 0.5 centimeter thick glass with 0.3 centimeters of vacuum between them
OD.
1.0 centimeter thick steel
What will happen to the volume of the gas when the temperature is increased?
Explain your answer
can I have a short answer that explains everything cause my teacher hates me so much lol
Answer:
the pressure will increase.this will cause the molecules of the gas will move faster and thats why the pressure or force increase the volume is the same
Which of the following is a molecule? *
1.He
2.Be
3.NO
4.Na