Answer:
Ammonia is a weak base with a standard pH level of about 11.
Explanation:
David delivers meals to elderly people once a week. He uses a cart to move the meals. The cart has four smooth wheels. Which type of friction acts between the cart wheels and the sidewalk?
A. sliding friction
B. rolling friction
C. fluid friction
D. static friction
Answer:Rolling
Explanation:
Since the wheels roll, the wheels do not rub against the sidewalk, So it cannot be sliding. The wheels are not a liquid, and there shouldnt be any static.
A 25.2 kg gazelle moving 2.33 m/s
sees a lion, and exerts a 113 N
force to accelerate. How fast is
it moving 2.00 s later?
The velocity of the gazelle after 2 seconds is equal to 11.3 m/s.
What is the equation of motion?The equations of motion have described the relationship between the time, velocity, acceleration, and displacement of a moving object.
The equations of motions can be described as shown below:
[tex]v = u + at\\S = ut +\frac{1}{2}at^2 \\ v^2-u^2 = 2aS[/tex]
Given the mass of the gazelle, m = 25.2 Kg
The force acting to accelerate, F = 113N
The acceleration in the speed of gazelle is given by: a = F/m
a = 113/ 25.2
a = 4.48 m/s²
The initial speed of the gazelle, u = 2.33 m/s
From the first equation of motion we can calculate the final velocity of the gazelle:
v = u + at
v = 2.33 + (4.48) (2)
v = 11.3 m/s
Therefore, the velocity of the gazelle 2 seconds later is 11.3 m/s.
Learn more about the equation of motion, here:
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How does the current values in and out of the battery compare to the sum of currents going through the light bulbs?
Note: This is for Parallel circuits.
A car is going 60.0 mi/h and has to stop in 6.0 seconds. What is the car’s acceleration?
Explanation:
Convert mi/h to ft/s.
60.0 mi/h × (5280 ft/mi) × (1 h / 3600 s) = 88.0 ft/s
Find the acceleration.
a = Δv / Δt
a = (0 ft/s − 88.0 ft/s) / 6.0 s
a = -14.7 ft/s²
The driver must accelerate the car at the average rate of
- 10 mile / hour-second
for 6 seconds .
Which has greater kinetic energy: a bullet that has a mass of 0.05 kg travelling at 2500 m/s, or a lorry that has a mass of 4500 kg and is moving at 50 m/s?
Answer:
its the lorry
Explanation:
The kinetic energy of the truck will be, 5625000 kg m/s and the kinetic energy of the bullet will be 156250 kg m/s. So the kinetic energy of the lorry will be higher than the kinetic energy of the Bullet.
What is Kinetic Energy?Kinetic energy is a type of energy that a particle or an object possesses as a result of its motion. By exerting a net force on an item, work is done, which transfers energy; as a result, the object accelerates and obtains kinetic energy.
A moving item or particle's ability to move depends on both its mass and velocity. This is known as kinetic energy. Translation (or movement along a path from one location to another), rotation about an axis, vibration, or any combination of motions are examples of possible types of motion.
According to the question,
K.E of the lorry: 1/2 (4500)(50)²
K.E of the lorry = 5625000 kg m/s.
K.E of the bullet: 1/2(0.05)(250)²
K.E of the bullet = 156250 kg m/s
Hence, the kinetic energy of the lorry is greater than the kinetic energy of the bullet.
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A paint brush is dropped from the top of a tall ladder and free falls to the ground. What changes, if any, would be observed of the velocity and the acceleration of the brush as it falls? Pick the two answers. The velocity increases. The velocity decreases. The velocity remains a constant value. The acceleration increases. The acceleration decreases. The acceleration remains a constant value.
Answer:
Explanation:
As the paint brush is dropped from the top of a tall ladder it started free falling
i.e. velocity of brush increases as it falls down due to the acceleration provided by gravity.
We know acceleration due to gravity is the attraction experienced by the object due to earth attraction
Value of acceleration due to gravity is constant i.e. [tex]9.8\ m/s^2[/tex]
Therefore the correct choice is
velocity is increasing and acceleration is constant
. How does the intensity of sunlight received affect Earth’s temperatures?
explain how muscles and bones work together to help bend the arm.
By contracting, muscles pull on bones and allow the body to move. ... For example, the biceps and triceps muscles work together to allow you to bend and straighten your elbow. When you want to bend your elbow, your biceps muscle contracts (Figure below), and, at the same time, the triceps muscle relaxes.
Answer:
By contracting, muscles pull on bones and allow the body to move. ... For example, the biceps and triceps muscles work together to allow you to bend and straighten your elbow. When you want to bend your elbow, your biceps muscle contracts (Figure below), and, at the same time, the triceps muscle relaxes.
What is the current in a 160V circuit if the resistance is 2Ω?
Answer:
80 amperes
Explanation:
Current = Voltage/Resistance
160/2 = 80
What is power?
A. a magnitude of a force needed to move an object
B. how much work can be done in a given time
C. the distance over time that an object moves
D, The energy needed to create work
Answer:
The answer is B.
Explanation:
The formula of power is :
[tex]power = \frac{work \: done}{time} [/tex]
* Work done can be "Energy"
What might be collected to monitor the amount of excess nitrogen in the local water system
Answer:
If excess nitrogen is found in the crop fields, the drainage water can introduce it into ... have aquifers that can supply a lot of freshwater very near the land surface.
How do coal deposits found in the U.S. and Serbia help prove the theory of continental drift?
Answer:
Wegner's hypothesis met with wide skepticism, but found support and development in ... theory because Wegener could not satisfactorily explain how the continents moved.
Explanation:
Some of his theory was proven wrong, but he was still correct about his hypothesis. The fossils were part of proof for the theory because some of the fossils were found on shore line. And, some of those animals couldn't swim. So, this is proof that some animals lived on the land. And over time the land drifted apart.
The ____ is a line drawn at a right angle to a barrier. a. normal c. node b. ray d. wave front
Answer:
a. normal
Explanation:
In the field of physics the normal is a line drawn at a right angle to a barrier. In other words the normal line is the line that is drawn perpendicular (right angle, 90 degrees) to the reflective surface of a mirror, or the particular boundary in which refraction occurs at the point of incidence of a light ray. This can be seen in the picture attached below.
Chef Andy tosses an orange in the air, then catches it again at the same height. The orange is in the air for 0.75\,\text s0.75s0, point, 75, start text, s, end text. We can ignore air resistance.
Answer:
3.68 m/s
Corrected question;
Chef Andy tosses an orange in the air, then catches it again at the same height. The orange is in the air for 0.75 s. We can ignore air resistance. What was the orange's velocity at the moment it was tossed into the air?
Explanation:
Applying the equation of motion;
v = u + at. ....1
Where
u = initial speed
v = final speed
a = acceleration
t = time taken
Given;
Total time of flight t = 0.75s
Acceleration due to gravity g = 9.8 m/s^2
Considering the first phase of flight, during the upward motion to the maximum height. The final velocity at the maximum height is zero and the time of flight of the phase is equal to half of the total flight time.
v1 = 0
t1 = t/2 = 0.75/2 =0.375s
From equation 1;
v1 = u - gt1
Substituting the values;
0 = u - 9.8(0.375)
Solving for u;
u = 9.8(0.375)
u = 3.675
u = 3.68 m/s
Initial velocity = 3.68 m/s
explain how muscles and bones work together to help bend the arm.
Answer:
Bones make sure the arms structure is stable while the muscle is the one actively moving it and carrying out actions.
Um joalheiro recebe uma encomenda onde ele deve fazer alguns anéis de prata. Ele dispõe de um pedaço de 100 g de prata mas precisa derrete-lo para colocar a prata em moldes específicos e construir esses anéis. O principal problema desse procedimento é que a temperatura de fusão da prata é muito alta e requer condições especiais. A prata possui temperatura de fusão de 961 ºC, calor latente de fusão de 21 cal/g e calor específico no estado sólido igual a 0,056 cal/gºC. Determine a quantidade de calor aproximada para fundir as 100 g de prata sabendo que sua temperatura inicial é de 20°C. A 2,1 kcal B 0,5 kcal C 7,4 kcal D 5,3 kcal E 6,3 kcal
Answer:
Correct option: C -> 7.4 kcal
Explanation:
First we need to find the energy necessary to heat the silver from 20°C to 961°. The change in temperature is 961 - 20 = 941, so the energy necessary is:
941 * 0.056 * 100 = 5269.6 cal
Then, for the melting process, we will need:
21 * 100 = 2100 cal
So the total energy needed is:
5269.6 + 2100 = 7369.6 cal = 7.4 kcal
Correct option: C
Each gas sample has the same temperature and pressure. which sample occupies the greatest volume? each gas sample has the same temperature and pressure. which sample occupies the greatest volume? 40.0 gar 20.0 gne 20.0 gh2 4.0 ghe
Answer:
20 gram of H as the greastest volume
Explanation:
Each gas sample has the same temperature and pressure. which sample occupies the greatest volume? each gas sample has the same temperature and pressure. which sample occupies the greatest volume? 40.0 gar 20.0 gne 20.0 gh2 4.0 ghe
Given that,
40.0 g of Ar
20.0 g of Ne
20.0 g of h
24.0 g of he
The ideal gas equation ; Pv = nRT
where P is the pressure, V is the volume, R is the gas constant, T is the temperature, n is the number of mole
which is equal to
n = m / M
where m is the given mass
M is the molar mass
The given gas sample are at the same temperature and pressure,
So, the temperature, pressure and gas constant are fixed.
Therefore the volume is proportional to the given mass and molar mass
V ∝ m/M
Substitute the given mass and molar mass of given masses for comparison
No of mole of Ar = mass / molar mass
= 40 / 40 = 1 mole
No of mole of Ne = mass / molar mass
= 20 / 20 = 1 mole
No of mole of h = mass / molar mass
= 20 / 1 = 20 mole
No of mole of he = mass / molar mass
= 24 / 4 = 6 mole
Hence, 20 gram of H as the greastest volume
You do 20 J of work pushing a crate up a ramp. If the output work from the inclined plane is 11 J, then what is the efficiency of the inclined plane?
Answer:
55%
Explanation:
take efficiency=power output/power input multiply by 100%
Remy wonders if the height of the mountain has anything to do with the eventual size of the tsunami wave. How should Remy test this? A. Cause avalanches on several different mountains and see how large each resulting tsunami is. B. Build different-sized model mountains at the edge of a pool, pour sand down the side of each mountain, and see how large each resulting wave is. C. Pour different amounts of sand down the side of a model mountain into a pool and see how large each resulting wave is. D. Build a model town at the edge of a pool and see how large waves must be to cause damage to the buildings.
Answer:
The answer is B
Explanation:
I got this from study island
Read the scenario. A car starts 10 m north of a reference point. It moves at a constant velocity over the next 5 s, reaching a position of 10 m south of the reference point. What is the car’s average velocity? 2 m/s south 4 m/s north 0 m/s 4 m/s south
Answer:
4 m/s south
Explanation:
This is a pretty easy one.
Assume that the car has a reference point ragged x
We also know that the car starts moving at a point 10 m North of X. It moves steadily at a uniform velocity and ended at a position 10 m south of X.
If x is the reference point, we can infer that the car moves a total distance of, 10 m + 10 m.
Thus, the total distance moved by the car is 20 m.
It is also stated that it achieves that distance in 5 seconds.
Velocity is defined as the ratio of distance with respect to the tome taken, i.e V = d/t
Then, the velocity is
V = 20 / 5 = 4 m/s
Considering the fact that the car left and moved towards the south. We can say that it moved 4 m/s South.
Mg + __HCl → MgCl2 + H2
What coefficient is needed to balance the equation?
Answer:
The coefficient of the blank is 2
Explanation:
The balanced equation is Mg + 2HCl -> MgCl2 + H2 .
Answer:
Mg + 2HCl → MgCl2 + H2
Explanation:
A boat travels at 30 mph for a huge, solid cliff that is about 3,000 meters away. When the horn on the boat makes a toot, you can hear the initial sound directly from the horn and also an echo from the cliff wall some time later. How does the frequency of the echo compare with the frequency of the horn before the ship moved?
Group of answer choices
The frequency of the echo is slightly increased.
The frequency of the echo is slightly decreased.
The frequency is unchanged.
Not enough information to determine.
Answer:The frequency of the echo is slightly decreased
Explanation:
Given
speed of boat [tex]=30\ mph[/tex]
cliff is [tex]3000\ m[/tex] away
when boat is still , suppose t is the time taken by the echo to reach observer on the boat
But as soon as boat starts moving the distance between cliff and boat decreasing and time for echo to reach observer also decreases
and we know [tex]time \propto \frac{1}{frequency}[/tex]
therefore frequency of the echo slightly decreased.
Jada’s family pulls into a gas station. Her mother fills up the car’s tank with fuel from a pump. Jada notices this symbol on the pump.
Image shows a pump at a gas station with a symbol of corn on it.
What do you think the symbol indicates?
A. This gasoline is to be used only in farm vehicles.
B. It is not safe to have gasoline around food products.
C. This gasoline can also be used as a fertilizer to help plants grow.
D. A biomass has been used as part of the fuel.
Answer:
D- a biomass has been used as a part of the fuel.
a 25 ohm resistor in an electric circuit draws a current of 5 amperes a certain amount of charge through the resistor in 36 seconds calculate the voltage
Answer:
V= 125volts
Explanation:
R =25ohms
I = 5 amp
V = ?
t = 36seconds
V = IR
V = 5× 25
V= 125volts
Q = It
Q = 5×36
Q = 180 coulombs
Q is the amount of charge.
A boat at anchor is rocked by waves whose crests are 28 m apart and whose speed is 7 m/s. How often do these waves reach the boat? State your answer in terms of frequency (Hz) and period T (seconds).
Answer:
0.25 Hz
4 s
Explanation:
Speed = wavelength × frequency
7 m/s = 28 m × f
f = 0.25 Hz
Frequency = 1 / period
0.25 Hz = 1 / T
T = 4 s
Which of the following metric system units is used when measuring large quantities of water?
Gallons
Liters
mL
Cup
Answer:
I want to say Liters but not 100% sure
write a sentence explaining how tempature changes with altitude
when preasure decreases, air expands and it cools
Calculate the energy that 1.5 kg of mass contains
Answer:
[tex]4.5(10)^8[/tex] joules
Explanation:
Mass–energy equivalence is the principle that says that anything that has mass has an equivalent amount of energy. Converse is also true.
The relation between energy and mass is given by [tex]E=mc^2[/tex]
Here, E denotes energy, m denotes mass and c denotes speed of light
Mass [tex](m)=1.5\,\,kg[/tex]
Speed of light (c) = 3 × [tex]10^8[/tex] m/s
Therefore,
[tex]E=1.5(3)(10)^8=4.5(10)^8[/tex] joules.
The S.I. unit of energy is joules which is equal to [tex]1\,\,kg\,\,m^2/s^2[/tex]
How does visible light interact with objects to produce the colors we see?
Answer:
Visible light when all put together is white. When objects appear to be, lets say, red, it would be the only color not absorbed by that object. same goes with all other colors. So black objects absorb all colors (not 100%) and that is why black clothing gets hotter, it simply absorbs all incoming light, as apposed to white that will reflect the colors back, making all of them together appear white. Hope this helps, not the best at explaining things.
A rocket, launched from rest, steadily increases speed to 33m/s over a 3.6s
interval before exhausting all the fuel. The rocket continues upward but slows
steadily to a stop 2.8s after running out of fuel.
How far did the rocket rise while burning fuel?
Answer:4 miles
Explanation:
