Answer:
(a) =34.0J
(b) = 13.038m/s
(c) =
Explanation:
(a) mass (m) =0.45kg
Height(h) =8.5m
Gravity (g) =10m/s^2
But P. E (Potential Energy) = mass × gravity × height
P. E = 0.45×10×8.5
P. E = 34.0J
(b) using v^2=u^2 - 2gs
Where v = final velocity
u= initial velocity
g = gravity
s =distance
But at maximum height v =0
0^2= u^2 - 2gs
Transpose u^2 we have
u^2 = 2gs
u^2 = 2×10×8.5
u^2 = 170
u = square root of 170
u = 13.038m/s
I NEED HELP PLEASE, THANKS! :) Why is it a good idea to touch a metal pole, or similar conductor, before filling up a car with gas?
Answer:
While filling up the gas, a static discharge can take place which is really dangerous for us. It can even ignite a fire at the gas station. Touching the metal pole or any conductor will pass all of the charge into the Earth and thus we'll keep safe.
Answer:
It is a good idea to touch a metal pole or similar conductor before filling up a car with gas because it will discharge any static electricity on you, making it safer for everyone.
Explanation:
does anyone know question 6?
Answer:
Yes, the fuse will blow.
Explanation:
We'll begin by converting 50000mA to amperes (A) .this is illustrated below:
1000mA = 1A
Therefore, 50000mA = 50000/1000 = 50A.
From the question given above, the plug can only accommodate 5A. Now if 50000mA i.e 50A is passed through the plug, the plug will blow because the 50A is higher than what the plug can accommodate.
I NEED HELP PLEASE, THANKS!
Find or draw at least two pictures that illustrates Newtons first Law. Write a paragraph describing how each of the pictures you choose illustrates the law.
Explanation:
When a person is standing still, the forces acting on them (weight force pulling down and normal force pushing up) are equal and opposite, so the net force is balanced. So the person will continue to be at rest, unless the net force becomes unbalanced.
When a person falls with a parachute, the forces acting on them (weight force pulling down and air resistance pushing up) are equal and opposite, so the net force is balanced. So the person will continue to fall at the same speed until the net force becomes unbalanced.
A train starts from rest .It moves through 1km in 100s with uniform accelaration . What will be its speed at the end pf 100 s
Answer:
Explanation:
Distance = 1 km
= 1000m
Time = 100 sec
Speed = distance / time
= 1000 / 100
= 10 m/s
A 72-kg skydiver is falling from 10000 feet. At an instant during the fall, the skydiver
encounters an air resistance force of 540 Newtons. The acceleration of the skydiver at
this instant is
m/s2
Answer:
Approximately [tex]2.31\; \rm m \cdot s^{-2}[/tex] (assuming that the acceleration due to gravity is[tex]g = 9.81\; \rm m \cdot s^{-2}[/tex].)
Explanation:
Assuming that [tex]g = 9.81\; \rm m \cdot s^{-2}[/tex] the weight on this 72-kg skydiver would be [tex]W = m \cdot g = 72 \; \rm kg \times 9.81\; \rm m \cdot s^{-2} = 706.32\; \rm N[/tex] (points downwards.)
Air resistance is supposed to act in the opposite direction of the motion. Since this skydiver is moving downwards, the air resistance on the skydiver would point upwards.
Therefore, the net force on this skydiver should be the difference between the weight and the air resistance on the skydiver:
[tex]\begin{aligned}F(\text{net force}) &= W - F(\text{air resistance})\\ &= 706.32\; \rm N - 540\; \rm N =166.32\; \rm N \end{aligned}[/tex].
Apply Newton's Second Law of motion to find the acceleration of this skydiver:
[tex]\begin{aligned}a &= \frac{F(\text{net force})}{m} \\ &= \frac{166.32\; \rm N}{72\; \rm kg} = 2.31\; \rm m \cdot s^{-2} \end{aligned}[/tex].
A boy throws a baseball onto a roof and it rolls back down and off the roof with a speed of 3.80 m/s. If the roof is pitched at 38.0° below the horizon and the roof edge is 3.30 m above the ground, find the time the baseball spends in the air and the horizontal distance from the roof edge to the point where the baseball lands on the ground. HINT
Answer:
a) The baseball spends 0.674 seconds in the air
b) The horizontal distance from the roof edge to the point where the baseball lands on the ground = 2.02 m
Explanation:
The ball's initial speed, u = 3.8 m/s
θ = 38°
The edge of the roof has a height, H = 3.30 m
The vertical motion of the baseball can be given by the equation:
[tex]H = U_{y} t + 0.5a_{y} t^{2}[/tex].........(1)
Vertical acceleration of the baseball, [tex]a_y = 9.8 m/s^2[/tex]
The vertical component of the initial speed can be calculated by:
[tex]U_y = Usin \theta\\U_y = 3.8 sin 38\\U_y = 2.34 m/s[/tex]
Substituting the appropriate values into equation (1):
[tex]3.8 = 2.34 t + 0.5(9.8)} t^{2}\\4.9t^2 + 2.34t - 3.8 = 0[/tex]
Solving for t in the quadratic equation above:
t = 0.674 s
To calculate the horizontal distance, S, use the formula below:
[tex]S = U_xt + 0.5a_xt^2[/tex]
Horizontal acceleration of the baseball, [tex]a_x = 0 m/s^2[/tex]
The horizontal component of the initial speed can be calculated as:
[tex]U_x = Ucos \theta\\U_x = 3.8 cos 38\\ U_x = 2.99 m/s[/tex]
S = 2.99(0.674) + 0.5(0)
S = 2.02 m
Jessica stretches her arms out 0.60 m from the center of her body while holding a 2.0 kg mass in each hand. She then spins around on an ice rink at 1.1 m/s.
a. What is the combined angular momentum of the masses?
b. If she pulls her arms into 0.15 m, what is her new linear speed?
I'm really confused ab the explanations behind this. help, please
Answer:
a.) L = 2.64 kgm^2/s
b.) V = 4.4 m/s
Explanation: Jessica stretches her arms out 0.60 m from the center of her body. This will be considered as radius.
So,
Radius r = 0.6 m
Mass M = 2 kg
Velocity V = 1.1 m/s
Angular momentum L can be expressed as;
L = MVr
Substitute all the parameters into the formula
L = 2 × 1.1 × 0.6 = 1.32kgm^2s^-1
the combined angular momentum of the masses will be 2 × 1.32 = 2.64 kgm^2s-1
b. If she pulls her arms into 0.15 m,
New radius = 0.15 m
Using the same formula again
L = 2( MVr)
2.64 = 2( 2 × V × 0.15 )
1.32 = 0.3 V
V = 1.32/0.3
V = 4.4 m/s
Her new linear speed will be 4.4 m/s
3.-¿ Como actuarias tú, si en pleno juego el árbitro toma una decisión, apesar de estar equivocado?¿finalizado el encuentro te despedirias del arbitro? Si - No ¿Porqué?
Answer:
Comprobar explicación
Explanation:
Si el árbitro toma una decisión en el medio del juego, a pesar de estar equivocado, normalmente, como humano, las emociones están destinadas a superarlo, pero de acuerdo con el reglamento, hay conductas aceptables y una protesta llena de emociones. en el árbitro puede salirse de las manos y conducir a más castigos de acuerdo con los libros de reglas.
Después del partido, por lo general, aún me despediría y expresaría mi desagrado tan cortésmente como pueda, pero porque cuando uno se equivoca, las emociones que lo acompañan pueden volverse increíblemente incontrolables, por lo tanto, es mejor mantener el control y no obtener castigado aún más.
¡¡¡Espero que esto ayude!!!
You have a graduated cylinder that you use to measure volume. The cylinder
is marked in 1 ml increments. Which measurement made using this cylinder
contains the correct number of significant digits?
A. 35.5 ml
B. 320.01 ml
C. 75.333 ml
D. 21 ml
Answer:
35.5 ml
Explanation:
The other guy made me get the question wrong lol here ya go good luck
Which property of sugar makes it different from white crystalline sand?
Answer:
The property of sugar which makes it different from sand is that sugar can dissolve in water. Explanation: however the power of dissolving of sand is not present. This is due to the presence of interaction between sugar and water.
Explanation:
I hope that was useful
Place the types of radiation in order of INCREASING mass.
Answer & explanation:
Gamma Radiation (γ): Also called gamma rays. Gamma radiation is made of electromagnetic waves, has zero charge and mass, continuously emits heat and has the ability to ionize air and make it conductive of electric current. Beta radiation (β): Beta rays or beta particles, are electrons, negative particles with charge - 1 and mass number 0.Alpha radiation (α): Also called alpha particles or alpha rays, are particles charged by two protons and two neutrons. They have positive charge +2 and mass number 4.I NEED HELP PLEASE, THANKS :) What does it mean when white light is diffracted and at a particular location the color seen is blue?
Answer:
This is because white light consists of 7 colours with different angles o deviation or retraction.
Explanation:
When a narrow beam of light is refracted by a prism the light spreads into a band of colours (called the spectrum of light )
But in this case if a blue colour is observed it is due to the angle of refraction ,for instance red is refracted the least and hence is seen
Answer:
When while light is diffracted and at a particular location blue color is seen, this means that blue color is reflected while all other colors will be absorbed. When the blue color is seen denotes the shortest wavelength being reflected and all other being absorbed at the specified location.
A magnetic field exerts a force of 0.25 N on an 8.0 cm length of wire carrying a current of 3.0 A at right angles to the field. Calculate the force that the same field would exert on another wire 20 cm long carrying the same current. I WILL GIVE BRAINLY
Answer: 0.625N
Explanation:
Given the following:
Magnetic field Force = 0.25N
Length of wire = 8cm
Current = 3.0 ampere
The force that the same field will exert on another wire 20cm long carrying the same current will be :
Since current 'I' is the same ;
0.25 Force = 8cm
x force = 20cm
Cross multiply:
8x = (20 × 0.25)
x = (20 × 0.25) / 8
x = 5 / 8
x = 0.625
Force = 0.625N
Answer:
A magnetic field exerts a force of 0.25 N on an 8.0 cm length of wire carrying a current of 3.0 A at right angles to the field. Calculate the force that the same field would exert on another wire 20 cm long carrying the same current. I WILL GIVE BRAINLY
Explanation:
hi please I need help with my mMATHEMATICS ASSIGNMENTS
1. Find the value of x and y in the following ratios
a. 3:5 = x:20
b.11:35 = 66: y
2. In a village of 375 children under the age of 10. If 68% of them have had malaria, how many children have escaped the disease?
3. Five buses need 3 trips to take 450 students to the stadium to watch a concert. How many trips would the 3 buses need to take the same number of students?
4. The ratio of girls to boys in a boarding school is 2:7. If there are 1,251 students in the school:
a. How many of the students are girls?
b. What percentage of the students are boys?
5. An old carpet which now costs #1 000, was sold for #1 400 when new. Calculate the percentage decrease.
6. The cost of petrol is #65 per litre. What is the percentage increase if it is sold for #105 per litre by a dealer during fuel scarcity?
Answer:
1
(a) Ans we are applying the formula
product of means = product of extremes
So according to the formula 5x = 60
x= 60/5
x = 12
(b) Ans we are applying the formula
product of means = product of extremes
2310=11 y
y = 2310/11
y = 210
Explanation:
(a)In product of means we multiply inner values with each other like in this case for solution of a part 5 and x are inner values and in product of extremes we multiply outer value like in case of solution for a 3 and 20 are outer values.
To which category does galaxy #4 belong? Why does it belong in this category?
Answer:
The Galaxy IV satellite belongs to the HS-601 model category. It was engineered by Hughes Space and Communications Company (HSC)
Explanation:
The Galaxy IV belong in this category because it is a communications satellite. It was built for direct television broadcasting, for private business networks and mobile communications.
Cheers!
a loop with a break in it that prevents current form flowing is called a(n) blank circuit
Answer: it is called a open circuit
Explanation:
What activity level should participants be in when exercising in their target heart rate zone
Answer:
La frecuencia cardíaca objetivo durante las actividades de intensidad moderada es aproximadamente del 50 al 70% de la frecuencia cardíaca máxima, mientras que durante la actividad física intensa es de, aproximadamente, entre el 70 y el 85% del valor máximo.
All matter is made up of________ called atoms or molecules
A gas baloon bursts when comes to a high altitude.... Plss answer it
Answer:yess
Explanation:as weather balloons travels from the earth's surface, the air pressure around ballons decreases slowly.As the air gets thinner,the gallons casing gets tighter.
This is due to gas expanding within balloon.The expanding gas causes the balloons to reach maximum height and it burst.
Which of the following represents the equation of motion of a steel ball thrown into a viscous liquid when it is moving with an acceleration a ?(A) W-V-U=ma (B)W-U=ma-V (C)W-U-V=0 (D)U-V=W
Answer: A
Explanation: When a steel ball is thrown into a viscous liquid, three forces will act on the ball.
1.) The viscous drag force V which is acting upward
2.) The buoyant force U which is acting upward and
3.) The weight of the ball W. Which is acting downward.
When it is moving with an acceleration a, the weight W will be greater than U and V
Since Force = ma.
The resultant vector force will be
W - V - U = ma
A ray diagram is shown what does the letter x represent?
Answer: angle of incidence
Answer:
A) angle of incidence
Explanation:
Find the average velocity if the takeoff velocity of an airplane on a runway is 300 km/hr with an acceleration of 1 m/s2 . A) 30 sec B) 41.7 sec C) 72.2 sec D) 83.33 sec
Answer:
83.33s
Explanation:
velocity=300km/hr ,acceleration =1m/s2
But before we can make this calculation,we have to make sure that both the acceleration and velocity are in the same units.So I decided to Chang the velocity to m/s.
Converting 300km/hr into m/s;
Changing 300km into m=300000m
Changing 1hr into secs=3600sec
Velocity in m/s=83.33m/s
But Time =velocity/acceleration
=83.33/1
=83.33sec
You have to decide what you want. Your question says "Find the average velocity", but the choices you listed are all times, not velocities.
(300 km/hr) x (1 hr / 3600 sec) = 83.33 meters/sec
-- If the airplane starts from rest and accelerates uniformly at 1 m/s², it'll take 83.33 seconds to reach takeoff speed.
-- If it starts from rest and accelerates uniformly to 83.33 m/s, then its average speed is 41.67 m/s no matter what its acceleration may be.
I NEED HELP PLEASE, THANKS! Describe each Newton Law. :)
Explanation:
1st- states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction.
2nd- states that the time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it. (most important law)
3rd- states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction. (law of action/reaction)
A uniform metal tube of length 5m and mass 9kg is suspended by two vertical wires attached at 50cm and 150cm respectively from the ends of the tube. Find the tension in each wire
Answer:
force (tension) of 29.4 N (upward) in 100 cm
force (tension) of 58.4 N (upward) in 200 cm
Explanation:
Given:
Length of tube = 5 m (500 cm)
Mass of tube = 9
Suspended vertically from 150 cm and 50 cm.
Computation:
Force = Mass × gravity acceleration.
Force = 9.8 x 9
Force = 88.2 N
So,
Upward forces = Downward forces
D1 = 150 - 50 = 100 cm
D2 = 150 + 50 = 200 cm
And F1 = F2
F1 x D1 = F2 x D2
F1 x 100 = F2 x 200
F = 2F
Total force = Upward forces + Downward forces
3F = 88.2
F = 29.4 and 2F = 58.8 N
force (tension) of 29.4 N (upward) in 100 cm
force (tension) of 58.4 N (upward) in 200 cm
e)
The surface area of foot of Bimaba is 150cm? If she weighs 50kg,
how much pressure does she exert on the ground, as she stands on
her one foot? (32666.67 pa)
Answer:
Pressure, P = 32666.66 Pa
Explanation:
It is given that,
Surface area of foot of Bimaba is 150 cm² or 0.015 m².
Her weight is 50 kg
We need to find the pressure does she exert on the ground, as she stands on her one foot. The force acting per unit area is called pressure. It can be given by :
[tex]P=\dfrac{F}{A}\\\\P=\dfrac{mg}{A}\\\\P=\dfrac{50\times 9.8}{0.015}\\\\P=32666.66\ Pa[/tex]
So, the pressure is 32666.66 Pa.
Which is an example of a fission reaction? Check all that apply.
H + H → He 2n
+
239 Pu + n + 1904 Ce + Kr + 2n
295 Am + in → 154 La + 95 Sr + 3 in
13C + H + 4N
Answer:
Check Explanation
The fission reactions include
239 Pu + n → Ce + Kr + 2n
And
295 Am + in → 154 La + 95 Sr + 3 n
Explanation:
A fission reaction is a radioactive reaction in which an atom with a heavy nuclei splits into atoms with smaller or lighter nuclei usually brought about by the attack of a fundamental particle and accompanied by the release of some fundamental particles (neutrons mostly) and energy.
Although, the reactions to be examined aren't totally clear, we can still guess which element is which and know which of the reactions has a heavier nuclei splitting into smaller ones.
1) H + H → He + 2n
Two hydrogen atoms combine to give an helium atom and release neutrons too, showing that here, smaller molecules combine to form a bigger one. Hence, this isn't a fission reaction, rather, it's a fusion reaction.
2) 239 Pu + n → Ce + Kr + 2n
Here, Pu (Plutonium, atomic mass 239), a heavy nuclei that splits into smaller nuclei, Ce (Cerium, atomic mass 140) and Kr (Krypton, atomic mass 84) together with some neutrons to fit the definition of a fission reaction. Hence, this reaction is a fission reaction.
3) 295 Am + n → 154 La + 95 Sr + 3 n
Here, Pu (Americium, atomic mass 295), a heavy nuclei that splits into smaller nuclei, Ce (Lamthanium, atomic mass 154) and Sr (Strontium, atomic mass 95) together with some neutrons to fit the definition of a fission reaction. Hence, this reaction is a fission reaction.
4) 13C + H → 14N
Carbon 13 combines with a hydrogen element to mutate and give nitrogen-14, a heavier nuclei, showing all signs of a nuclear fission and not fission.
Hope this Helps!!!
Answer:
b and c
Explanation:
got it correct on edg
The coldest layer of Earth’s atmosphere is the __________. a. troposphere c. mesosphere b. stratosphere d. thermosphere
Answer: c.mesosphere
Explanation: Temperatures can reach lows of -90 degrees Celsius in the mesosphere, making it the coldest layer of the earth's atmosphere. The mesosphere extends above the stratosphere and ranges from 50 km to 87 km above the surface.
A diverging lens of focal length 18.0m is used to view a shark that is 90.0m away from the lens. If the image formed is 1.0m long, calculate the: (i) image distance; (ii) length of the shark.
Answer:
i. + 22.5 m ii. 4.0 m
Explanation:
i. Image distance
Using the lens formula
1/u + 1/v = 1/f where f = focal length = + 18.0 m, u = object distance = distance of shark away from lens = + 90.0 m and v = image distance from lens = unknown
So, we find v
1/v = 1/f - 1/u
= 1/+18 - 1/+90
= (5 - 1)/90
= 4/90
v = 90/4
= + 22.5 m
So the image is real and formed 22.5 m away on the other side of the lens.
ii Length of Shark
Using the magnification formula, m = image height/object height = image distance/object distance. image height = 1.0 m where object height = length of shark.
m = image distance/object distance
= v/u
= +22.5/+90
= 0.25
0.25 = image height/object height
So,
object height = image height/0.25
= 1.0 m/0.25
= 4.0 m
So, the length of the shark is 4.0 m
What type of bond is most likely to form between atoms of the same element when the element is a metal?
Answer:Covalent bond
Explanation:
The fatty layer contains many nerves and blood vessels. True or False
Answer:
False , The fatty layer do not contains many nerves and blood vessels. The fatty layer is related to skin layers.
Explanation:
The fatty layer is the most under a layer of skin. It made up of a system of collagen and fat cells. It helps maintain the body's temperature and shields the body from harm by serving as a shock absorber.
The dermis is the central layer of the skin. The dermis is maintained collectively by a protein termed collagen. This layer gives skin elasticity and power. The dermis also holds shock and feel receptors.