Answer:
Continental drift describes one of the earliest ways geologists thought continents moved over time. Today, the theory of continental drift has been replaced by the science of plate tectonics.
The theory of continental drift is most associated with the scientist Alfred Wegener. In the early 20th century, Wegener published a paper explaining his theory that the continental landmasses were “drifting” across the Earth, sometimes plowing through oceans and into each other. He called this movement continental drift.
A 45.7 kg woman starts from rest at the bottom of a flight of stairs that has
a total height of 2.54 meters. She reaches the top of the stairs
in 5.00 seconds. How much power does she generate if she is moving at
2.63 m/s at the top of the stairs? Use g = 9.8 m/s2, and only include 3
numbers in your answer.
Answer:
The power generated by the woman is 259 W
Explanation:
Given;
mass of the woman, m = 45.7 kg
initial velocity of the woman, u = 0
total height ascended by the woman, h = 2.54 m
time of the woman's motion, t = 5.0 s
final velocity of the woman, v = 2.63 m/s
acceleration due to gravity, g = 9.8 m/s²
The potential energy of the woman due to the height she ascended;
P.E = mgh
P.E = 45.7 x 9.8 x 2.54
P.E = 1137.564 J
The kinetic energy of the woman due to her final velocity;
K.E = ¹/₂mv²
K.E = ¹/₂ x 45.7 x (2.63)²
K.E = 158.051 J
The total mechanical energy of the woman at the top of the stairs;
M.E = P.E + K.E
M.E = 1137.564 J + 158.051 J
M.E = 1295.615 J
The power generated by the woman;
Power = Energy/time
Power = 1295.615 J / 5 s
Power = 259.123 W
Power = 259 W
An ideal horizontal spring-mass system is set into motion. At an instant when the mass passes through its equilibrium position: The potential energy in the spring is at its _____. The kinetic energy of the mass is at its ______. The magnitude of net force acting on the mass is at its ______.
Answer:
the potential energy is zero, and the kinetic energy must be maximum
F = 0
Explanation:
In this exercise you are asked to complete the sentences of a simple harmonic movement of a mass-spring system.
In this system mechanical energy is conserved
at the most extreme point the carousel potential energy is
K_e = ½ k x²
the kinetic energy is zero for that stopped.
At the equilibrium point
the spring elongation is x = 0 so the potential energy is zero
and the kinetic energy must be maximum since total energy of the system is conserved
the spring force is
F =- k x
as in the equilibrium position x = 0 this implies that the force is also zero
F = 0
In this exercise we have to use the knowledge of force to calculate the energy of a spring, in this way we find that:
The potential energy in the spring is at its [tex]K_e = 1/2 k x^2[/tex]. The kinetic energy of the mass is at its zero . The magnitude of net force acting on the mass is at its Zero.
In this system mechanical energy is conserved, at the most extreme point the carousel potential energy is:
[tex]K_e = 1/2 k x^2[/tex]
The kinetic energy is zero for that stopped or when at the equilibrium point, so:
the spring elongation is x = 0 so the potential energy is zero the kinetic energy must be maximum since total energy of the system is conserved
the spring force is:
[tex]F =- k x\\F=0[/tex]
See more about force at brainly.com/question/26115859
A.) A gemstone of mass 1.8 kg compresses a scale's spring by 2.6 cm.
Determine the spring constant.
B.) How much would the spring in the previous question compress if a 5.2 kg mass was placed on the scale?
Explanation:
Given that,
Mass, m = 1.8 kg
Compression, x = 2.6 cm
We know that,
Force on spring = weight
So,
[tex]mg=kx[/tex]
Where
k is spring constant
[tex]k=\dfrac{mg}{x}\\\\k=\dfrac{1.8\times 9.8}{2.6\times 10^{-2}}\\\\k=678.46\ N/m[/tex]
(2) If m = 5.2 kg
[tex]x=\dfrac{mg}{k}\\\\x=\dfrac{1.8\times 9.8}{678.46}\\\\x=2.6 \ cm[/tex]
Hence, this is the required solution.
Water enters a shower head
through a pipe of radius 0.0112 m
at 3.75 m/s. It flows through 25
small holes, each of radius
0.001200 m. At what speed does
water come out of the shower
head? (Don't forget, there are 25
holes, not 1.)
(Unit = m/s)
Answer:
13.1
Explanation:
thats what i put in for acellus and its right
1. An atom that loses electrons has a ________________________ charge and an atom that gains
electrons has a ___________________________ charge.
Charged atoms are called ___________________.
2. What is an insulator? Give 4 examples.
3. What is a conductor? Give an example.
4. How can we move electrons from one place to another? What actually causes the electrons to
move?
5. Static electricity is ______________________________________________________________________
_______________________________________________________________________________________
6. Explain the attraction and repulsion of charges.
7. Why does a balloon stick to the wall?
8. Why does your hair stand up when you take off your hat?
9. Why do you get a shock when you walk across a carpet?
10. When is static electricity most noticeable and why?
11. State the Principle of Conservation of Charge.
12. The invisible electric force field around charged objects depends on __________________________,
__________________________, and _____________________________.
13. What is the relationship between the charges and the field strength?
What is the relationship between the field strength and the distance between the charges?
1. What is DC?
What is AC?
2. Name 3 ways to get DC.
3. What is an electrical circuit?
4. What is voltage?
What is current?
What is resistance?
What causes heat and light in a wire?
COPY THE TABLE comparing water in a hose-DC-units
5. Which electricity do we use in our homes?
CLICK ON ALTERNATING CURRENT
1. Explain AC.
2. Who invented the light bulb?
3. Who really invented AC?
4. Who discovered the advantages of AC over DC?
5. How is AC made?
6. What is the main advantage of AC over DC?