A student said,Today, giraffes have long necks that allow them to eat leaves high in trees. They got longer necks by stretching up for even higher leaves. After many generations, the giraffe’s neck was really long.Do you think the student’s explanation for how the giraffe’s neck became long is correct? Explain.
Answer:
yes because there is also a theory about this I studied in biology
theory name -Lamarck's theory
A TV has a power of 65 watts and an efficiency of 70 percent. How much
power is wasted as heat?
A. 19.5 W
B. 2.2 W
C. 0.9 W
D. 45.5 W
Power of TV = 65Watt
If Efficiency = 70%, then the percentage of energy wasted is 30%
So, the amount of energy getting wasted:
= 30/100 × 65
= 1950/100
= 195/10
= 19.5 W
An argon gas occupies 56.2 L at 760 torr. If the volume of gas dereases to 1/4 of the original volume ,calculate its final pressure
Answer:
3040 torr
Explanation:
Applying,
PV = P'V'..................... Equation 1
Where P = Initial Pressure, V = Initial volume, P' = Final pressure, V' = Final volume.
Make P' the subject of the equation
P' = PV/V'................. Equation 2
From the question,
Given: P = 760 torr, V = 56.2 L, V' = 56.2/4 = 14.05 L
Substitute these values into equation 2
P' = (56.2×760)/14.05
P' = 3040 torr
Help fast please physics
Answer:
10
Explanation:
Pop up spring Lab
Describe the energy conversion that took place. What energy was present just before the jump? What energy is present at its maximum height? What happens in between?
Draw bar charts of energy before the jump, while the spring toy is compressed and after the jump at the maximum height of its jump. Be sure to label each type of energy.
Answer:
I honestly don't know but that thing looks cool lol
A 56.6-kg crate rests on a level floor at a shipping dock. The coefficients of static and kinetic friction are 0.517 and 0.260, respectively. What horizontal pushing force is required to (a) just start the crate moving and (b) slide the crate across the dock at a constant speed
Answer:
Explanation:
Magnitude of frictional force = μ mg
μ is either static or kinetic friction.
To start the crate moving , static friction is calculated .
a ) To start crate moving , force required = μ mg where μ is coefficient of static friction .
force required =.517 x 56.6 x 9.8 = 286.76 N .
b ) to slide the crate across the dock at a constant speed , force required
= μ mg where μ is coefficient of kinetic friction , where μ is kinetic friction
= .26 x 56.6 x 9.8 = 144.21 N .
A blow-dryer and a vacuum cleaner each operate with a voltage of 120 V. The current rating of the blow-dryer is 14 A, while that of the vacuum cleaner is 4.2 A. Determine the power consumed by (a) the blow-dryer and (b) the vacuum cleaner. (c) Determine the ratio of the energy used by the blow-dryer in 16 minutes to the energy used by the vacuum cleaner in 43 minutes.
Answer:
The correct solution is:
(a) 1680 W
(b) 504 W
(c) 1.240
Explanation:
The given values are:
Voltage,
V = 120 V
Current of blow dryer,
I₁ = 14 A
Current of vacuum cleaner,
I₂ = 4.2 A
Time,
t₁ = 16 min
t₂ = 43 min
As we know,
⇒ [tex]Power (P) = VI[/tex]
(a)
For blow dryer:
⇒ [tex]P_1=V\times I_1[/tex]
[tex]=120\times 14[/tex]
[tex]=1680 \ W[/tex]
(b)
For Vacuum cleaner:
⇒ [tex]P_2=V\times I_2[/tex]
[tex]=120\times 4.2[/tex]
[tex]=504 \ W[/tex]
(c)
The ratio will be:
= [tex]\frac{Blow \ dryer \ energy}{Vacuum \ cleaner \ energy}[/tex]
= [tex]\frac{P_1\times t_1}{P_1\times t_2}[/tex]
= [tex]\frac{1680\times 16}{504\times 43}[/tex]
= [tex]\frac{26880}{21672}[/tex]
= [tex]1.240[/tex]
PLS HELP. URGENT.
I WILL MARK HIM/HER AS BRAINLIEST.
Answer:
Explanation:
frequency=1/time period
50=1/time
time=1/50
time=0.020 s
Answer: A
Explanation:
What is the strength of an electric field 0.2 m from a 1.56 x 10-6 C charge?
Answer:
Solution given:
strength of electric field [E]:?
distance[d]:0.2m
charge[Q]=[tex]1.56×10^{-6} C[/tex]
we have
E =K [tex] \frac{Q}{r²}[/tex]
E=[tex]9×10^{9} C[/tex][tex] \frac{1.56×10^-6 C}{0.2²} [/tex]
E=[tex] 3.51×10^{5}[/tex]V/m
strength of electric field : [tex] 3.51×10^{5}[/tex]V/m
A student uses the circuit shown to determine the resistance of two identical resistors.
H--
А.
V
The voltmeter reading is 2.2V and the ammeter reading is 0.25A.
What is the resistance of each resistor?
A 0.2752
B
0.552
C 4.4Ω
D
8.82
Answer:
B. 0.552
Explanation:
To find the resistance in the circuit above, u simply divide the current in the circuit by the voltage to get the resistance.
58
74
3 points
A hummingbird beats its wings up and down with a frequency of 100 Hz. What is the period of the hummingbirds flaps? (D
YOUR ANSWER)
59
Answer:
T = 0.01 s
Explanation:
Given that,
The frequency of the beats of a hummingbird, f = 100 Hz
We need to find the period of the hummingbirds flaps. Let the time is t. We know that the relation between frequency and time period is given by :
T = 1/f
Put all the values,
T = 1/100 = 0.01 s
So, the time period of the humming bird is 0.01 s.
A bus travels to and from a school that is located 10 km to the west. What is the distance? What is the displacement?
20 km
Hope this helps Have a good day
Solve for resistance. I do not get it. Pls help
Answer: I think a
Explanation:
One pot has a water height of 8cm. Calculate the water pressure at the bottom of the pot. They give g = 10N / kg p = 1000kg / m3
Answer:
P = 800 Pa
Explanation:
The pressure of water at the bottom of the pot can be given by the following formula:
[tex]P = \rho g h[/tex]
where,
P = Pressure at the bottom of the pot = ?
ρ = density = 1000 kg/m³
h = height of water = 8 cm = 0.08 m
Therefore,
[tex]P = (1000\ kg/m^3)(10\ m/s^2)(0.08\ m)[/tex]
P = 800 Pa
please help with this question
Answer:
This unbalanced force causes her to change in direction.
If the forces on an object are unbalanced, this is what happens:
a stationary object starts to move in the direction of the resultant force
a moving object changes speed and/or direction in the direction of the resultant force
The distance between two successive crests of a certain transverse wave is 1.40 m. Eight crests (7 waves) pass a given point along the direction of travel every 15.0 s. How fast are the waves traveling
Answer:
the speed of the wave is 0.65 m/s
Explanation:
Given;
distance between two successive crests, λ = 1.4 m
number of crests, n = 8
number of waves formed = 7
The total distance covered by the wave, d= 7λ = 7 x 1.4 = 9.8 m
time of motion of the wave, t = 15 s
The speed of the wave is calculated as;
V = d/t
V = 9.8 / 15
V = 0.65 m/s
Therefore, the speed of the wave is 0.65 m/s
In an electric circuit, 40 C of electric charge pass a point in 5.0 s.
What is the current in the circuit?
A 0.13A
B
8.0A
C 45A
D
200 A
Answer:
Explanation:
current=amount of charge/time taken
=40/5
=8 ampere(A)
The current flowing in the circuit is 8 A.
The correct answer to the question is Option B. 8 A.
Quantity of electricity, current and time are related by the following equation:
Q = ItWhereQ is the quality of electricity.
I is the current.
t is the time.
With the above formula, we can obtain the current in the circuit as illustrated below:Quantity of electricity (Q) = 40 C
Time (t) = 5 s
Current (I) =?Q = It
40 = I × 5
Divide both side by 5
I = 40 / 5
I = 8 AThus, the current in the circuit is 8 A.
The correct answer to the question is Option B. 8 A
Learn more: https://brainly.com/question/21690385
A rookie quarter back throws a football with an initial upward velocity component of 12.0 m/s and a horizontal velocity component of 20.0 m/s. Ignore resistance. How much time is required for the football to reach the highest point of the trajectory
Answer:
t = 1.22 s
Explanation:
Given that,
The initial upward velocity component of a football = 12 m/s
The horizontal velocity component is 20 m/s
We need to find the time required for the football to reach the highest point of the trajectory. Let the time is t.
Using first equation of motion to solve it such that,
[tex]v=u+at[/tex]
u is initial velocity
v is final velocity
a = -g
so,
[tex]t=\dfrac{u}{g}\\\\t=\dfrac{12}{9.8}\\\\t=1.22\ s[/tex]
So, the required time taken by the football to reach the highest point is 1.22 seconds.
Give your answer to 2 dp
When taking off a plane accelerates at 2.7m/s2 down the runway. It accelerates from a stationary position for 25 seconds before leaving the ground. What
is the planes speed when it leaves the ground?
Answer:
67.5
Explanation:
The plane accelerates at 2.7m/s,^2
Time is 25 seconds
The velocity can be calculated as follows
= 25×2.7
= 67.5
Hence the speed f the plane is 67.5
The Keck Observatory is home to the largest Earth-based twin telescopes. The telescopes are located away from city lights, above the clouds where the atmosphere is clear, calm, and dry. In 1999, additional steps were taken to help the telescopes overcome any distortions caused by changes in the atmosphere by adding a laser sighting system. Now, the Keck telescopes can probe distant galaxies and capture images with more detail than even the Hubble Space Telescope. Scientists can now use the Keck telescopes to investigate many questions. What is one question the Keck telescopes would NOT help scientists answer
Answer:
Option D
Explanation:
The options for the question are
a) How do galaxies rotate?
b) What is the weather on Neptune?
c) What is the core of Saturn made of?
d) What other solar systems have planets?
Solution
The Hubble space telescope was designed and integrated into the extraterrestrial system in order to capture information about the surrounding universe. If the Keck Observatory has a better observation capacity than the Hubble space telescope then the scientist would be interested to know the surrounding planets in the solar system.
Hence, option D is correct
Eroded debris that is dropped at the glaciers farthest extent when ice melts at the front of the glacier as seen in the image is called
A. Terminal Moraines
B. Lateral Moraines
c. Gradient
D. Striations
Answer:
A) terminal moraines
Explanation:
Moraines are the rocks and sediments deposited by moving glaciers. Terminal means the end, the furthest the glacier travels. Lateral means what's deposited along the sides of the moving glacier.
which clock do scientists use to measure time why
Scientists use Atomic clock to measure time
How do you find a wavelength?
G.P.E = weight (n) x height (m). 2 identical twins are skiing down 2 different slopes. one is 1000m high, the other is 1500 m high. the twin at 1000m weighs 150 N. the other twin weighs 100 N. which twin has the most P.E before they begin skiing?
Answer:
I don't know i really I'm sorry I wish I could help
Suppose that Joe and Jim are twins and :
________________________________
Joe :
Height = 1000 m
==》 PE = 150 × 1000
Weight = 150 N
==》 PE = 150,000 j
_________________________________
Jim :
Height = 1500 m
==》PE = 100 × 1500
Weight = 100 N
==》PE = 150,000 j
______________________________
As u can see Joe and Jim has equal PE before they begin skiing .
A 5 kg ball is thrown at 4 m/s. What is the ball’s momentum
Answer:
20kgm/s
Explanation:
p=mv
p=5*4
p=20kgm/s
The force of ____________ exists between any two objects that have mass.
free fall
acceleration
weight
gravity
Answer:
gravity
Explanation:
Two forces of 8N and 10N CANNOT give a resultant of
a. 1 N
b. 2 N
c. 9 N
d. 18 N
Answer:
I believe it is D
forgive me if I'm wrong
(GIVE ME THE ANSWER OR YOU'LL GET REPORTED) Can someone answer this for me with the steps tysm
Answer:
Direction: north-west (45 degrees)
Magnitude: 500 N
Explanation:
The wind exerts a force upwards, a.k.a. north.
The water exerts a force to the left, or west.
The directions are 90 degrees apart from each other, so the angle of the je force is 45 degrees (north-west).
We can use the Pythagorean theorem to calculate the magnitude.
[tex]a^2+b^2=c^2\\400^2+300^2=250000^2\\\sqrt{250000} = 500N[/tex]
1
The distance between objects, along with the masses of the object, affect the gravitational force between the objects. Which
statement is TRUE according to Newton's law of universal gravitation?
O When the masses of objects increase, gravitational force decrease
O When the distance between objects increases, gravitational force decreases.
O When distances between objects decreases, gravitational force decreases
O When the masses of objects decrease, the distance between objects decreases.
Every object in the universe attracts every other object with a force along a line joining them. The force is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers of mass.
The energy principle states that:
Energy can be destroyed.
Energy can be created.
Energy cannot be created or destroyed.
Energy cannot be created, but it can be destroyed.
brainleist to correct answer
The energy principle states that:
[tex]\sf\purple{Energy \:cannot \:be \:created \:or\: destroyed.✅}[/tex]
Law of conservation of energy or the first law of thermodynamics states that energy can neither be created nor destroyed; it can only be transferred or changed from one form to another.[tex]\large\mathfrak{{\pmb{\underline{\orange{Happy\:learning }}{\orange{.}}}}}[/tex]