Answer:
B. low melting points and low densities
Explanation:
Alkali metals are any of the monovalent elements found in Group IA of the periodic table. They readily lose their one valence electron to form ionic compounds with nonmetals. Examples of alkali metal are Potassium (K), Lithium (L), and Sodium (Na).
Compared to most other metals, the chemical properties that alkali metals have are low melting points (28.5°C) and low densities that is typically less than 1 grams per cubic centimeters.
A 50 kg go cart is located at the top of a 10 m tall hill….sitting motionless. It goes down the hill and rises to the top of the second hill while have a speed of 1 m/s. How tall is the second hill?
Answer:
Explanation:
This is a Law of Momentum Conservbation problem, where the total energy of the system cannot increase or decrease, only change form. The total energy equation for this situation is
TE = PE + KE where TE is total energy, PE is potential energy, and KE is kinetic energy. We begin by realizing that the go-kart is motionless at the top of a hill. If the kart isn't moving, then it has no KE, but if it is up off the ground and has the potential to fall to a point lower than it is curremtly, it has potential energy. That means that the total energy available to this go-kart is found in its potential energy and will not change throughout the trip's entirety. Thus,
TE = PE + 0 and
TE = (50.0)(9.8)(10.0) so
TE = 4900 J and since that's the total energy available throughout the trip, and we are looking to find the height of the next hill where this is both potential and kinetic energy, then
4900 = PE + KE and
4900 = (50.0)(9.8)(h) + [tex]\frac{1}{2}(50.0)(1.0)^2[/tex] and
4900 = 490h + 25.0 and
4875 = 490h so
h = 9.9 m (I kinda ignored the rules for significant digits at the end, which goes against every teacher's bone in my body, but nonetheless, there's your answer!)
a student drops a ball off the top of building and records that the ball takes 3.32s to reach the ground (g=9.8 m/s^2). what is the ball's speed just before hitting the ground?
Answer:
Explanation:
Use the one-dimensional equation for motion
v = v₀ + at and filling in,
v = 0 + (-9.8)(3.32) so
v = -33 m/s (negative because it is going downwards and upwards is positive).
if you use 75 N of force to lift and object and you do 300 Joules of work how far did you lift the object?
Given W (work) = 300J
F (force) = 75N
s (displacement) = ?
We know that, W = Fs
So,
300 J = 75N × s
= 300J/75N = s
= 4m = s
So, I traveled 4m.
Is the equation balanced?
2H2O + O2 = 4MgO + 3Fe
Answer:
no
Explanation:
the equation can't be balanced because it doesn't have the same elements on each side of the equal sign.
The given equation is not a balanced chemical equation because it does not contain the same elements on both sides of the equation.
What is the balanced chemical equation?A chemical equation can be explained as the representation of a chemical reaction in terms of symbols of the substances. A balanced equation containing the same number of atoms of each element on either side of the equation.
The law of mass conservation is followed by every balanced chemical equation. By obeying this law, the total mass on the reactant side should be equal to the total mass on the product side in a balanced equation.
On both sides of the chemical equation, the same elements as well as an equal number of elements are present as the chemical reaction does not alter the identity of the elements. Therefore, the given equation is not a balanced chemical equation.
Learn more about the balanced chemical equation, here:
brainly.com/question/28294176
#SPJ2
how do you do question 2?
Answer:
Look at explanation
Explanation:
a) Weight is another term for how much gravity is on an object and can be calculated by using the local gravity*mass so in order to find weight divide 1200 by g
m= 1200/9.8= 122.45kg
b) We know Fnet=ma and Fnet=Fapp+Fresistivity so Fapp+Fresistivity=ma
Plug in values
500+Fresistivity=122.45*2
solve for Fresistivty= 244.9-500=-255.1N (the reason it is negative is because it is in the opposite direction
c)Power= ΔE/Δt and we also know ΔE=ΔWork so Power= ΔWork/Δt. If a person pulls harder, they have a greater force and since mass is constant, acceleration is greater and since the amount of time needed to cover A to B is reduced since x-x0=v0t+1/2at²(v0=0, when you solve for t it will be lower because acceleration increases). If t decreases than Power increases by inverse proportionality. Work =Fd if the amount of Force increases by distance travelled remains constant than work also increases so power will also increase.
In the year 2090, and Burt is still alive! Well, he’s really just a brain connected to a “life machine.” Since Burt has no body, he doesn’t experience physiological responses such as changes in heartbeat, perspiration, or breathing. Yet Burt still experiences many different emotions. The theory of emotion that best explains how Burt can experience these emotions is_______________________________________
A James-Lange theory
• B Cannon-Bard theory
• C Schachter–Singer theory
Define second class lever
Answer:
Please find detailed explanation of second class levers below
Explanation:
Levers are one of the classes of machine that possesses three levels namely: first class, second class and third claas. A second class lever is the level of levers in which the load (L) is in between the pivot (F) and the effort (E).
Examples of second class levers include; wheelbarrow, a bottle opener etc. In the bottle opener for example, the bottle lid (load) is in between the pivot of the opener and the hand opening it (effort).
Our galaxy, the ______________, contains more than 200 billion stars.
Answer: Milky Way
Explanation:
A capacitor stores 7.77 x 10-7 J of
energy when 4.29 x 10-8 C of
charge is on the plates. What is the
voltage across the capacitor?
[?] V
No links please
Answer: [tex]36.22\ V[/tex]
Explanation:
Given
Energy in a capacitor [tex]E=7.77\times 10^{-7}\ J[/tex]
Charge [tex]Q=4.29\times 10^{-8}\ C[/tex]
Energy of a capacitor is given by
[tex]E=\dfrac{1}{2}CV^2=\dfrac{1}{2}QV\quad [\text{Q=CV}][/tex]
Insert the values
[tex]E=\dfrac{1}{2}QV\\\\\Rightarrow 7.77\times 10^{-7}=\dfrac{1}{2}\times 4.29\times 10^{-8}\times V\\\\\Rightarrow V=3.622\times 10\\\\\Rightarrow V=36.22\ V[/tex]
Thus, the voltage around the capacitor is [tex]36.22\ V[/tex]
A car traveling 77 km/h slows down at a constant 0.48 m/s2 just by "letting up on the gas." A) Calculate the distance the car coasts before it stops. B)Calculate the time it takes to stop. C)Calculate the distance it travels during the first second. D)Calculate the distance it travels during the fifth second.
Answer:
(a) 477 m
(b) 44.6 s
(c) 21.16 m
(d) 19.24 m
Explanation:
initial speed, u = 77km/h = 21.4 m/s
acceleration, a = - 0.48 m/s2
final speed v = 0
(a) let the stopping distance is s.
Use third equation of motion
[tex]v^2 = u^2 + 2 a s\\\\0 = 21.4^2 - 2 \times 0.48\times s\\\\s = 477 m[/tex]
(b) Let t is time.
Use first equation of motion
v = u + at
0 = 21.4 - 0.48 t
t = 44.6 s
(c) Let the distance is s in first second.
Use second equation of motion
[tex]s = u t + 0.5 at^2\\\\s = 21.4\times 1 - 0.5\times 0.48\times 1\\\\s = 21.4 - 0.24 = 21.16 m[/tex]
(d) distance traveled in 5 th second is given by
[tex]s = u + 0.5 a (2 n - 1) \\\\s = 21.4 - 0.5\times 0.48 \times (2\times 5 -1)\\\\s= 21.4 - 2.16 = 19.24 m[/tex]
i have 5 eggs i grabbed one i a cracked 1 i cooked one i ate one how many eggs do i have
Answer:
4
Explanation:
4-3
Lead has a density of 11. 5 g/cm³. A rectangular block of lead measures 7 cm x 5 cm x 2 cm.
a) Find the volume of the block of lead.
b) Find the mass of the block of lead.
(Please give step-by step explanations as well.)
Thank you!
Answer:
A = 70cm³
B= 805 grams
Explanation:
(a) V = L×B×H
= 7cm × 5cm × 2cm
= 35cm × 2cm
= 70cm³
(b) Mass= volume × Density
= 70cm³ × 11.5g/cm³
=805 grams
I hope this will help you ...
PLEEEASEEEEEE HELPPPPP PLEASEEEEEEEEEE science
Answer:
A
Explanation:
transverse wave
Hope this helps you!
describe 2 ways you could increase the efficiency of a household central heating system
Answer:
Arrange an annual service. Treat your boiler like your car. ...
Keep your boiler clean. ...
Bleed your radiators. ...
Top up the pressure. ...
Use a Powerflush. ...
Insulate your pipes. ...
Turn the heating on. ...
If all else fails…
Explanation:
I am a combination of strength and speed, What am I?
Muscular Endurance
Flexibility
Power
Body Composition
Answer:
Power
step by step explanation:
Ciara is swinging a 0.015 kg ball tied to a string around her head in a flat, horizontal circle. The radius of the circle is 0.50 m. It takes the ball 0.70 seconds to complete one full circle. Calculate the tension in the string and its direction that provides the centripetal force acting on the ball to keep it in the circular path.
A. 0.60 N, along the line tangent to the circle
B. 0.015 N, along the line tangent to the circle
C. 0.60 N, toward the center of the circle
D. 0.015 N, toward the center of the circle
Answer:
Option C
Explanation:
From the question we are told that:
Mass [tex]m=0.015kg[/tex]
Radius [tex]r=0.5m[/tex]
Time [tex]t=0.70[/tex]
Generally the equation for Tension is mathematically given by
[tex]T=\frac{4mr}{t^2} \pi[/tex]
[tex]T=\frac{4*0.015*0.5}{(0.70)^2} (3.142)[/tex]
[tex]T=0.60N[/tex]
Therefore
[tex]T=0.60 N[/tex], toward the center of the circle
Option C
Answer:
0.60 N, toward the center of the circle
Explanation:
Got it right on the test.
Use the information from the graph to answer the question. What is the acceleration of the object
Answer:
-2.5 m/s²
Explanation:
The acceleration of a body is the change in it's velocity with time.
The change in velocity with time can be obtained as the slope of a velocity time graph ;
Acceleration = (change in velocity / change in time)
Taking the slope :
Change in Velocity = △y = y2 - y1
Change in time = △x = x2 - x1
(10, 15) ; (0, 40)
△y / △x = y2 - y1 / x2 - x1 = (40 - 15) / (0 - 10)
△y / △x = 25 / - 10 = - 2.5 m/s²
A 62.0 kg water skier at rest jumps from the dock into a 775 kg boat at rest on the east side of the dock. If the velocity of the skier is 4.50 m/s as she leaves the dock, what is the final velocity of the skier and boat?
2.78 m/s to the east
2.78 m/s to the west
0.360 to the west
0.360 to the east
Answer:
The final velocity of the skier and boat is 0.33 m/s to the east.
Explanation:
We can find the final velocity of the skier by conservation of linear momentum:
[tex] m_{s}v_{s_{i}} + m_{b}v_{b_{i}} = m_{s}v_{s_{f}} + m_{b}v_{b_{f}} [/tex]
Where:
[tex]m_{s}[/tex]: is the mass of the water skier = 62.0 kg
[tex]m_{b}[/tex]: is the mass of the boat = 775 kg
[tex]v_{s_{i}}[/tex]: is the initial velocity of the skier = 4.50 m/s (as she leaves the dock)
[tex]v_{b_{i}}[/tex]: is the initial velocity of the boat = 0 (it is at rest)
[tex]v_{s_{f}}[/tex]: is the final velocity of the skier =?
[tex]v_{b_{f}}[/tex]: is the final velocity of the boat =?
Since the final velocity of the skier is the same that the velocity of the boat ([tex]v_{f}[/tex]) we have:
[tex] m_{s}v_{s_{i}} + 0 = v_{f}(m_{s} + m_{b}) [/tex]
[tex]v_{f} = \frac{m_{s}v_{s_{i}}}{m_{s} + m_{b}} = \frac{62.0 kg*4.50 m/s}{62.0 kg + 775 kg} = 0.33 m/s
Therefore, the final velocity of the skier and boat is 0.33 m/s to the east.
I hope it helps you!
_________ on a body is produced by the gravitational force of attraction
Answer:
weight
Explanation:
Weight is the force of gravity with which a body is attracted towards the earth.
6d A boy pushes his little brother on a sled. The sled accelerates from rest to (4 m/s). If the combines of his brother and the sled is (40.0 kg) and (20 W) of power is developed, how long time does the boy push the sled?
Answer:
16 s
Explanation:
From the question given above, the following data were obtained:
Mass (m) = 40 Kg
Velocity (v) = 4 m/s
Power (P) = 20 W
Time (t) =?
Next, we shall determine the energy. This can be obtained as follow:
Mass (m) = 40 Kg
Velocity (v) = 4 m/s
Energy (E) =?
E = ½mv²
E = ½ × 40 × 4²
E = 20 × 16
E = 320 J
Finally, we shall determine the time. This can be obtained as follow:
Power (P) = 20 W
Energy (E) = 320 J
Time (t) =?
E = Pt
320 = 20 × t
Divide both side by 20
t = 320 / 20
t = 16 s
Thus, the time is 16 s
3 Draw energy transfer diagrams
for:
a) winding up a clockwork car
b) letting a clockwork car run
c) letting a battery-powered car
run.
Answer:
The outline of the energy transfer are;
a) Kinetic energy → Clockwork spring → Potential energy
b) Potential energy in clockwork car → Clockwork spring coil unwound → Clockwork car run
c) Chemical potential energy → Batteries in the car → Electric motors → Kinetic energy
Please find attached the drawings of the energy transfer created with MS Visio
Explanation:
The energy transfer diagrams are diagrams that can be used to indicate the part of a system where energy is stored and the form and location to which the energy is transferred
a) The energy transfer diagram for the winding up a clockwork car is given as follows;
Mechanical kinetic energy is used to wind up (turn) the clockwork car such that the kinetic energy is transformed into potential energy and stored in the wound up clockwork as follows;
Kinetic energy → Clockwork spring → Potential energy
b) Letting a wound up clockwork car run results in the conversion of mechanical potential energy into kinetic (energy due tom motion) energy as follows;
Potential energy in clockwork car → Clockwork spring coil unwound → Clockwork car run
c) The energy stored in the battery of a battery powered car is chemical potential energy. When the battery powered car runs, the chemical potential energy produces an electromotive force which is converted into kinetic energy as electric current flows from the batteries
Therefore, we have;
Chemical potential energy → Batteries in the car → Electric motors → Kinetic energy
when is the acceleration of body is positive negative and zero?
Answer:
【 In vector form , if angle between velocity vector and acceleration vector is less than 90° and greater than 0° then it is positive acceleration and if it is less than 180° and greater than 90° then it is negative acceleration. If there is no acceleration vector then it is called zero acceleration. 】
True or false please help I’ll give brainliest
Answer:
1 is false 2 is true 3 is false
Paco was driving his scooter west with an initial velocity of 4 m/s. He accelerates at 0.5 m/s2 for 30 seconds. What is his final velocity?
Answer:
19m/s
Explanation:
U= 4m/s
a = 0.5m/s²
t= 30s
V= U+at
= 4+15
=19m/s
What is a cyclotron??
What is cyclotron frequency?
Answer:
A cyclotron is a type of particle accelerator.
Explanation:
Cyclotron frequency is the frequency of a charged particle moving perpendicular to the direction of a uniform magnetic field B, since that motion is always circular, the cyclotron frequency is given by equality of centripetal force and magnetic Lorentz force.
A system is best described as: a. a form of energy that is transferred between two substances at different temperatures. b. mass that assumes a physical shape and occupies space. c. any set of ordered, interrelated components working as a unified whole. d. the capacity to change the motion of, or to do work on, matter. e. the point at which characteristics can no longer be maintained and a new state is adopted.
WILL MARK BRAINLIEST
Answer:
152,155 J
Explanation:
115,333 + 36,822 = 152,155J
A 70 jug astronaut is floating free in space several meters from her spacecraft. She is holding a1.6 kg wrench which she can hurl with a speed of 22.0 m/s. What will be her speed towards the spacecraft?
Answer:
0.5 m/s
Explanation:
In solving this, we would be applying the principle of conservation of momentum. This states that momentum is conserved, and thus, Initial momentum has to be equal to the final momentum. This also means that it can be related by the formula
M * u = m * v, where
M = mass of the astronaut
m = mass of the wrench
u = speed of the astronaut
v = final speed of the wrench
70 * u m/s = 1.6 * 22 m/s
70u = 35.2 m/s
u = 35.2/70
u = 0.5 m/s
What is another way to describe the vector below?
"40 feet to the right"
A. 40 feet to the left
B. -40 feet to the left
C. -40 m to the left
D. 40 m to the left
Answer:
-40 feet to the left
Explanation:
opposite of 40 feet from right is -40 to left
Answer:
B. -40 feet to the left
4. Một nguồn điện ba pha đối xứng nối hình sao, điện áp ba pha nguồn Up = 220V. Nguồn điện cung cấp cho tải 3 pha đối xứng nối tam giác. Biết dòng điện dây Id = 10A. Tính điện áp dây, dòng điện pha của tải và của nguồn.
Answer:
so you gotta bring the 5 and add to 7