Answer:
a) quantity to be measured is the height to which the body rises
b) weighing the body , rule or fixed tape measure
c) Em₁ = m g h
d) deformation of the body or it is transformed into heat during the crash
Explanation:
In this exercise of falling and rebounding a body, we must know the speed of the body when it reaches the ground, which can be calculated using the conservation of energy, since the height where it was released is known.
a) What quantities must you know to calculate the energy after the bounce?
The quantity to be measured is the height to which the body rises, we assume negligible air resistance.
So let's use the conservation of energy
starting point. Soil
Em₀ = K = ½ m v²
final point. Higher
Em_f = U = mg h
Em₀ = Em_f
Em₀ = m g h₀
b) to have the measurements, we begin by weighing the body and calculating its mass, the height was measured with a rule or fixed tape measure and seeing how far the body rises.
c) We use conservation of energy
starting point. Soil
Em₁ = K = ½ m v²
final point. Higher
Em_f = U = mg h
Em₁ = Em_f
Em₁ = m g h
d) to determine if the energy is conserved, the arrival energy and the output energy must be compared.
There are two possibilities.
* that have been equal therefore energy is conserved
* that have been different (most likely) therefore the energy of the rebound is less than the initial energy, it cannot be stored in the possible deformation of the body or it is transformed into heat during the crash
PLEASE HELP ME WITH ONE QUESTION
If 1000 J of heat energy is lost from a piece of hot metal which is placed into a cup of cool water, how much energy is gained by the water?
Answer:
1000J
Explanation:
According to the law of calorimetry;
Heat lost by cold substance = Heat gained by hot substance
If 1000 J of heat energy is lost from a piece of hot metal,
heat lost by hot substance = 1000J
Since we are to determine how much energy is gained by the water, using the law
Heat lost by hot metal = heat gained by the water
Hence heat gained by the water = 1000J
A cart moves with negligible friction or air resistance along a roller coaster track. The cart starts from rest at the top of a hill of unknown height. It then goes down that first hill and up another circularly shaped hill of height 10 meters and radius 15 meters. The ride is designed so that the cart just barely loses contact with the track at the top of the second hill (10 meters above ground level). What is the height of the starting hill relative to ground
Answer:
hinit = 17.5 m
Explanation:
Assuming no friction present, the mechanical energy must be conserved, which means that at any point of the trajectory, the sum of the gravitational potential energy and the kinetic energy must keep the same.At the top of the hill, since it starts from rest, all the energy must be potential, and we can express it as follows:[tex]E_{o} = U_{o} = m*g*h_{init} (1)[/tex]
When the car arrives to the top of the second hill, as we know that it is lower than the first one, the energy of the car, must be part gravitational potential energy, and part kinetic energy.We can express this final energy as follows:[tex]E_{f} = U_{f} + K_{f} = m*g* h_{2} + \frac{1}{2} *m*v_{f} ^{2} (2)[/tex]
In order to find hinit, we need to make (1) equal to (2), and solve for it.In (2) we have the value of h₂ (10 m), but we still need the value of the speed at the top of the second hill, vf.Now, when the car is at the top of the hill, there are two forces acting on it, in opposite directions: the normal force (upward) and the weight (downward).We know also that there is a force that keeps the car along the circular track, which is the centripetal force.This force is just the net downward force acting on the car (it's vertical at the top), and is just the difference between the weight and the normal force.If the cart just barely loses contact with the track at the top of the second hill, this means that at that point the normal force becomes zero.So, the centripetal force must be equal to the weight.The centripetal force can be expressed as follows:[tex]F_{c} = m*\frac{v_{f} ^{2}}{R} (3)[/tex]
We have just said that (3) must be equal to the weight:[tex]F_{c} = m*\frac{v_{f} ^{2}}{R} = m*g (4)[/tex]
Simplifying, and rearranging, we can solve for vf², as follows:[tex]v_{f}^{2} = R*g (5)[/tex]
Replacing (5) in (2), simplifying and rearranging in (1) and (2) we finally have:[tex]h_{init} = h_{2} + \frac{1}{2} R = 10m + 7.5 m = 17.5 m (6)[/tex]
how much force is needed to accelerate a 2500kg car at a rate of 4m/s2
Answer:
10,000 N
Explanation:
Using Newton's Second Law of Motion, Force = Mass*Acceleration.
Plugin 2500 kg for the mass and 4 m/s^2 for the acceleration.
Force = 2500 kg*4 m/s^2 = 10000 Newtons
(SI unit of force is Newtons)
Two resistors R1 = 3 Ω and R2 = 6 Ω are connected in parallel. What is the net resistance in the circuit?
Answer:
2ohms
Explanation:
the net resistance is given by
1/R=1/R1 +1/R2,we are supposed to find R
thus by making R the subject ....
R=R1•R2/R1+R2
R=3•6/3+6
R=18/9 =2Ohms
Which types of reactions are also redox reactions?
Answer:
Your ans is B)
Explanation:
Hope its right
if wrong firgive me
given that two vectors A=i,2j-2k and B=6i+3j+2k find A +B
Answer:
7i, 5j, 0k
Explanation:
Add up the two vectors.
Add
i+i 1+6 = 7i
j+j 2+3 = 5j
k+k -2+2 = 0k
therefore A+B = (7i, 5j, 0k)
Gaseous sulfur dioxide is a compound that combines with water in the atmosphere to form acid rain. What is the primary source of sulfur dioxide?
O volcanic emissions
O combustion of fossil fuels
O destruction of tropical forests
O mining and mineral extraction
A projectile is thrown with a velocity of 40 m/s, 45 degrees above the +x-axis. Determine its initial x-velocity and its initial y-velocity.
x-component is V·cos(angle)
y-component is V·sin(angle)
When the angle is 45°, its sin and cos are both 1/2·√2 .
Vx = 20·√2 = 28.28 m/s
Vy = 20·√2 = 28.28 m/s
PLZ HELP PLZ ILL GIVE BRAINLIEST TO BEST ANSWERED
The Earth's gravity pulling on a skydiver: Contact or Non Contact
Friction from a car's brakes causing it to stop: Contact or Non Contact
The repulsive magnetic force between the north poles of two magnets: Contact or Non Contact
The attractive electrostatic force between an electrically charged balloon and a wall: Contact or Non Contact
Answer:
1.Contact because its a contact force
2 Contact because when the car is stopping it is coming in to contact with the ground.
3 non Contact because magnets don't need to have contact they pull
4 non Contact because its not a contact force
1. Why is the flow of electrons from A to B?
2. What's the difference between flow of current & flow of electrons and why ar they opposite?
1. because A is more negative than B. A is -1000 V (we can imagine that A has excess 1000 electrons), in other, B which +3000 V can be assume that B need 3000 elctrons to be neutral. So, the electron will flow from A to B.
2. Electrons being negatively charged flow from the negative terminal to the positive terminal of the voltage source. So, the actual direction of current should be from negative to positive terminal. However, the conventional direction had already been established. So, the current flow is considered in the direction opposite to the direction of flow of electrons. (from topperlearning dot com)
A uniform 140 g rod with length 57 cm rotates in a horizontal plane about a fixed, vertical, frictionless pin through its center. Two small 30 g beads are mounted on the rod such that they are able to slide without friction along its length. Initially the beads are held by catches at positions 11 cm on each sides of the center, at which time the system rotates at an angular speed of 23 rad/s. Suddenly, the catches are released and the small beads slide outward along the rod. Find the angular speed of the system at the instant the beads reach the ends of the rod. Answer in units of rad/s.
Answer:
The correct answer is "12 rad/s"
Explanation:
The given values are,
Mass of rod,
M = 140 g
i.e.,
= 0.14 kg
Length,
L = 57 cm
i.e.,
= 0.57 m
Mass of beads,
M = 30 g
i.e.,
= 0.03 kg
Angular speed,
r = 11 cm
i.e.,
= 0.11 m
Now,
The inertia of rods will be:
= [tex]\frac{1}{12}ML ^2[/tex]
On substituting the values, we get
= [tex]\frac{1}{12}\times 0.14\times (0.57)^2[/tex]
= [tex]0.0037905 \ kg-m^2[/tex]
The inertia of beads will be:
= [tex]mr^2[/tex]
On substituting the values, we get
= [tex]0.03\times (0.11)^2[/tex]
= [tex]0.000726 \ kg-m^2[/tex]
The total inertia will be:
= [tex]Inertia \ of \ rods+Inertia \ of \ beads[/tex]
= [tex]0.0037905 + 0.000726[/tex]
= [tex]0.0045165 \ kg-m^2[/tex]
now,
The angular speed of the system will be:
⇒ [tex]L_1w_1=L_2w_2[/tex]
On substituting the values in the above equation, we get
⇒ [tex]0.0045165\times 23 = (0.0037905 + (0.03\times 0.285^2)\times 2 )\times w_2[/tex]
⇒ [tex]0.1038795 = 0.0037905 + (0.00243675\times 2 )\times w_2[/tex]
⇒ [tex]w_2 = 12 \ rad/s[/tex]
PLEASE HELP ME WITH THIS ONE QUESTION
Two substances of different temperatures are brought into thermal contact. While the objects come to equilibrium, some heat is lost to the environment. How would that affect the final temperature?
A) it would be higher
B) it would change unpredictably
C) it would remain the same
D) it would be lower
Answer:
the correct is D
Explanation:
In the calorimetry exercises, if there are no losses, we assume that all the heat lost by one body is absorbed by the other, but if there are losses
Q_ {yielded} = Q_ {absent} + Q_ {lost}
Since energy cannot be created or destroyed, they only ask to change, therefore the term of the absorbed heat must decrease, consequently the final temperature of the system is lower when there is loss of energy.
When checking the answers, the correct one is D
A human body consists of
Answer:
60% of the human adult body is water. According to H.H. Mitchell, Journal of Biological Chemistry 158, the brain and heart are composed of 73% water, and the lungs are about 83% water. The skin contains 64% water, muscles and kidneys are 79%, and even the bones are watery: 31%.
Explanation:
A police car drives with a constant speed of 70km/hr. how long will it take to cover a distance of 135km?
(btw, it's a physics question:-)
Explanation:
36. How long does it take a car to slow down from a speed of 54 km/h to 32 km/h over a distance of 65 m? Answer in seconds. 37.
1. Only about
% of water on Earth is fresh water that is readily available for human consumption.
a. less than 1
b. 5
c. more than 50
d. All water on Earth is fresh water and is easily accessible.
Answer:
Hey mate.....
Explanation:
This is ur answer....
a. Less than 1%3% of the earth's water is fresh. 2.5% of the earth's fresh water is unavailable: locked up in glaciers, polar ice caps, atmosphere, and soil; highly polluted; or lies too far under the earth's surface to be extracted at an affordable cost. 0.5% of the earth's water is available fresh water....
Hope it helps you,
Mark me brainliest plz....
Follow me! :D
Question:
1. Only about % of water on Earth is fresh water that is readily available for human consumption.
a. less than 1
b. 5
c. more than 50
d. All water on Earth is fresh water and is easily accessible
Answer:
a. less than 1
An electric motor supplies 2,500 Watts of power in a 220 V circuit. What is the resistance of the motor? Be sure to include the proper units in your answer. Remember... Ω is the unit for Resistance.
Answer:
R = 19.36 ohms
Explanation:
Given that,
The power of an electric motor, P = 2500 Watts
The voltage of the circuit, V = 220 V
We need to find the resistance of the motor. We can find it as follows :
[tex]P=\dfrac{V^2}{R}\\\\R=\dfrac{V^2}{P}\\\\R=\dfrac{(220)^2}{2500}\\R=19.36\ \Omega[/tex]
So, the resistance of the motor is 19.36 ohms.
Please please help I'm stuck!!!
Answer: iDc im in 3grade
Explanation:sorry
who compose the Ghana national anthem
Answer:
Philip Gbeho
Explanation:
Is there more than one way to get two objects with identical masses to balance? How?
Answer: yes you can
Explanation: because i i have a trying and a squar that have the same mass it would caunt as the same
Yes we can get two objects with identical masses to balance in this type of scenario.
What is Mass?
This is defined as the quantity of matter which is present in a body at a given point in time.
The two objects with identical masses can be made to balance through the use of a string and a pulley.
Read more about Mass here https://brainly.com/question/19385703
#SPJ9
a box is slides down a slope
Answer:
120 N
Explanation:
From the question given above, the following data were obtained:
Angle (θ) = 35°
Mass (m) = 15 Kg
Acceleration due to gravity (g) = 9.8 m/s²
Normal force (N) =?
The normal force acting on the object can be obtained as:
N = mg × Cosθ
N = 15 × 9.8 × Cos 35
N= 147 × 0.8192
N = 120 N
Therefore, the normal force acting on the object is 120 N
How to calculate the voltage of a light bulb
To teach you how to find the parameters characterizing an object in a circular orbit around a much heavier body like the earth.
The motivation for Isaac Newton to discover his laws of motion was to explain the properties of planetary orbits that were observed by Tycho Brahe and analyzed by Johannes Kepler. A good starting point for understanding this (as well as the speed of the space shuttle and the height of geostationary satellites) is the simplest orbit--a circular one. This problem concerns the properties of circular orbits for a satellite orbiting a planet of mass M. For all parts of this problem, where appropriate, use G for the universal gravitational constant.
1. Find an expression for the square of the orbital period.
2. The quantities v, K, U, and L all represent physical quantities characterizing the orbit that depend on radius R. Indicate the exponent (power) of the radial dependence of the absolute value of each.
Answer:
a) T² = ([tex]\frac{4\pi ^2}{GM}[/tex]) r³
b) veloicity the dependency is the inverse of the root of the distance
kinetic energy depends on the inverse of the distance
potential energy dependency is the inverse of distance
angular momentum depends directly on the root of the distance
Explanation:
1) for this exercise we will use Newton's second law
F = ma
in this case the acceleration is centripetal
a = v² / r
the linear and angular variable are related
v = w r
we substitute
a = w² r
force is the universal force of attraction
F = [tex]G \frac{m M}{r^2}[/tex]
we substitute
[tex]G \frac{m M}{r^2} = m w^2 r[/tex]
w² = [tex]\frac{GM}{r^3}[/tex]
angular velocity is related to frequency and period
w = 2π f = 2π / T
we substitute
[tex]( \frac{2\pi }{T} ) = \frac{GM}{r^3}[/tex]
the final equation is
T² = () r³
b) the speed of the orbit can be found
v = w r
v = [tex]\sqrt{\frac{GM}{r^3} } \ r[/tex]
v = [tex]\sqrt{\frac{GM}{r} }[/tex]
in this case the dependency is the inverse of the root of the distance
Kinetic energy
K = ½ M v²
K = ½ M GM / r
K = ½ GM² 1 / r
the kinetic energy depends on the inverse of the distance
Potential energy
U =
U = -G mM / r
dependency is the inverse of distance
Angular momentum
L = r x p
for a circular orbit
L = r p = r Mv
L =
L =
The angular momentum depends directly on the root of the distance
How do sociologists view the categories of race, class, and gender?
Multiple Choice
1. inherent and inevitable
2. socially constructed
3. unchangeable and perpetual
4. natural and biologically determined
Answer:
2. Socially constructed
Explanation:
The statement "If a plant receives fertilizer,
then it will grow to be bigger than a plant
that does not receive fertilizer" is an
example of
A. an observation.
B. a hypothesis.
C. a theory.
Charging by Contact examples
Answer:
the hair and the comb are both neutral
Please help
The period of an oscillation is measured to be 0.0833 seconds. What is
the frequency of this oscillation? *
1.0833 Hz
0.287 Hz
9.8 Hz
12 Hz
0.007 Hz
Answer:
your
answer is
12.004
An elevator motor in a high-rise building can do 3500 kJ of work in 5 min. Find the power developed by the motor. Explain if you can plz
Answer:
P = 11666.6 W
Explanation:
Given that,
Work done by the motor, W = 3500 kJ
Time, t = 5 min = 300 s
We need to find the power developed by the motor. Power developed is given by :
[tex]P=\dfrac{E}{t}\\\\P=\dfrac{3500\times 10^3}{300}\\\\P=11666.7\ W[/tex]
So, the required power is 11666.6 W.
The microwaves produced inside a microwave have a wavelength of 12.0m and a frequency of 25Hz. At what speed do the microwaves travel in units of m/s ?
Answer: 300 m/s
Explanation:
The equation for finding wave speed is the wavelength times the frequency which would be
12.0mx 25hz=300m/s
Find the velocity of a dolphin that swims 55 m in 5.0 s.
Answer: 11 m/s
Explanation: velocity = distance /time = 55 m /5.0 s
Answer:40km/h
Explanation:
help, it's an emergency !!!!!!!