Answer:
A. Looking at stick shadows on the equinox.
Explanation:
He measures the circumference by placing a pole when the sun is overhead on the days of solstice. He determined the circumference by measuring the difference between Alexandria to Syene and the angle of the pole's shadow.
The equation used for the calculation of circumference is as follow
[tex]\frac{360 degrew}{7.2 degree} = \frac{Circumference of earth}{Distance from Alexandria to Syene}[/tex]
Please refer to the following link for more details
https://www.khanacademy.org/humanities/big-history-project/solar-system-and-earth/knowing-solar-system-earth/a/eratosthenes-of-cyrene
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]
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.
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
Pls answer……………………..
2nd egg experienced more impulse
Hope this helps! :)
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 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
What is resistance? Difference between resistance and resistivity.
Answer:
Resistance is a measure of the opposition to current flow in an electrical circuit.All materials resist current flow to some degree. They fall into one of two broad categories: Conductors: Materials that offer very little resistance where electrons can move easily.
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
can someone please help
Answer:
Protein bars
Explanation:
Protein bars contain low-sugar and have high protein content and are therefore good source of nutrient when it is required to take food on-the-go so as to keep the muscle mass the same when it is not possible to take a meal on busy days or before workout
Protein bars can also be taken as part of easy and fast breakfast when travelling so as to maintain a balanced blood sugar level
PLEEEASEEEEEE HELPPPPP PLEASEEEEEEEEEE science
Answer:
A
Explanation:
transverse wave
Hope this helps you!
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).
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
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
Thermodynamics
Sad
064105 adt
What is energy required to melt (10.0 g) mass of aluminum that
is at its melting point? Knowing that the heat of fusion of
aluminum is (380 kJ/kg.)
Answer:
E = 3.8 kJ
Explanation:
Given that,
The mass of the object, m = 10 g = 0.01 kg
The heat of fusion of aluminum is 380 kJ/kg
We need to find the energy required to melt the mass of the aluminium. It can be calculated as follows:
E = mL
So,
E = 0.01 × 380
E = 3.8 kJ
So, the energy required to melt the mass is equal 3.8 kJ.
rocks from volcanoes are used by scientists to study the interior of the earth
TRUE OR FALSE
What is shunt resistance? How does it help in measuring current?
Answer:
it helps me
Explanation:
:))) ...
....
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 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!)
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
Our galaxy, the ______________, contains more than 200 billion stars.
Answer: Milky Way
Explanation:
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.
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).
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!
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 ...
Object A has twice the mass of object B. Both objects are moving at the same speed. Which accurately describes how inertia relates to Newton’s second law of motion in this example? Object A has twice the mass of object B. Both objects are moving at the same speed.
A. Object A requires twice the force to stop as Object B.
B. Object A requires one-and-a-half times the force to stop as Object B.
C. Object A requires four times the force to stop as Object B.
Answer:
A. Object A requires twice the force to stop as Object B.
Explanation:
Inertia can be defined as the tendency of an object or a body to continue in its state of motion or remain at rest unless acted upon by an external force.
Newton's Second Law of Motion states that the acceleration of a physical object is directly proportional to the net force acting on the physical object and inversely proportional to its mass.
Mathematically, it is given by the formula;
[tex] Acceleration = \frac {Net \; force}{mass} [/tex]
Let's assume the following values;
Mass of object B = 10 kg
Mass of object A = 2 * B = 2 * 10 = 20 kg
Acceleration = 5 m/s²
I. To find the force for B;
[tex] Force = mass * acceleration [/tex]
[tex] Force = 10 * 5 [/tex]
Force B = 50 Newton
II. To find the force for A;
[tex] Force = mass * acceleration [/tex]
[tex] Force = 20 * 5 [/tex]
Force A = 100 Newton
From the calculation, we can deduce that Force A (100 N) is twice or double the value of Force B (50 N).
In conclusion, since object A has twice the mass of object B and both objects are moving at the same speed, object A would require twice the force to stop as Object B.
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
_________ 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.
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
WILL MARK BRAINLIEST
Answer:
152,155 J
Explanation:
115,333 + 36,822 = 152,155J
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. 】