A person is standing on and facing the front of a stationary skateboard while holding a construction brick. The mass of the person is 67.0 kg, the mass of the skateboard is 4.10 kg, and the mass of the brick is 2.50 kg. If the person throws the brick forward (in the direction they are facing) with a speed of 23.0 m/s relative to the skateboard and we ignore friction, determine the recoil speed of the person and the skateboard, relative to the ground.
Answer:
v₁ = -0.8087 m / s
Explanation:
To solve this problem we can use the conservation of momentum, for this we define a system formed by the man, the skateboard and the brick, therefore the force during the separation is internal and the momentum is conserved
Initial instant. When they are united
p₀ = 0
Final moment. After throwing the brick
[tex]p_{f}[/tex] = (m_man + m_skate) v1 + m_brick v2
the moment is preserved
p₀ = p_{f}
0 = (m_man + m_skate) v₁ + m_brick v₂
v₁ = - [tex]\frac{ m_{brick} }{m_{man} + m_{skate} } v_{2}[/tex]
the negative sign indicates that the two speeds are in the opposite direction
let's calculate
v₁ = - [tex]\frac{2.5}{67 + 4.10} 23.0[/tex]
v₁ = -0.8087 m / s
Water runs out of a horizontal drainpipe at the rate of 135 kg/min. It falls 3.1 m to the ground. Assuming the water doesn't splash up, what average force does the water exert on the ground
Answer:
The average force exerted by the water on the ground is 17.53 N.
Explanation:
Given;
mass flow rate of the water, m' = 135 kg/min
height of fall of the water, h = 3.1 m
the time taken for the water to fall to the ground;
[tex]h = ut + \frac{1}{2}gt^2\\\\h = 0 + \frac{1}{2}gt^2\\\\t = \sqrt{\frac{2\times 3.1}{9.8} } \\\\t = 0.795 \ s[/tex]
mass of the water;
[tex]m = m't\\\\m = 135 \ \frac{kg}{min} \ \times \ 0.795 \ s \ \times \ \frac{1 \ \min}{60 \ s} \ = 1.789 \ kg[/tex]
the average force exerted by the water on the ground;
F = mg
F = 1.789 x 9.8
F = 17.53 N
Therefore, the average force exerted by the water on the ground is 17.53 N.
Why could it be argued that the respiratory system is most critical to sustaining life?
Explanation:
Energy is the most important ingredient for life. Organisms use energy in diverse ways. Scientifically, energy is defined as the ability to do work. Without this ability, organisms would not exist.
So, the most important process is one that can furnish the body with energy.
The respiratory system happens to be the one that furnishes the body with energy. During respiration, the energy needs of the body is met by series of processes. Oxygen is taken in and use to liberate calories from chemical substances packed with energy. So, without respiration, the bodily energy demands will not be met.Help please..................
A small mass is released from rest at a very great distance from a larger stationary mass. Draw a graphs best represents the gravitational potential energy U of the system of the two masses as a function of time T.
Answer:
attached below
Explanation:
Gravitational potential
energy = [tex]- \frac{GmM}{r}[/tex] ,
V ∝ [tex]- \frac{1}{r}[/tex]
attached below is a graph that represents the gravitational potential energy U
Gravitational potential energy is the energy held in an entity as a result of its vertical position or length. This gravitational pull of a planet on an object causes the information to be stored.
This is connected with gravitational pull since it takes work to lift anything against the gravity of the Earth.
Freshwater in a raised lake or kept behind a dam demonstrates gravitational force.
According to the formula:
Gravitational potential energy [tex]\bold{=-\frac{GMm}{r^2}}[/tex]
Therefore
[tex]\to \bold{V \propto -\frac{1}{r}}[/tex]
Therefore, the answer is "Option d"
Learn more about the Gravitational potential :
brainly.com/question/17001724
A small lead ball, attached to a 1.10-m rope, is being whirled in a circle that lies in the vertical plane. The ball is whirled at a constant rate of three revolutions per second and is released on the upward part of the circular motion when it is 1.3 m above the ground. The ball travels straight upward. In the absence of air resistance, to what maximum height above the ground does the ball rise
Answer:
1.84 m
Explanation:
For the small lead ball to be balanced at the tip of the vertical circle just before it is released, the reaction force , N equal the weight of the lead ball W + the centripetal force, F. This normal reaction ,N also equals the tension T in the string.
So, T = mg + mrω² = ma where m = mass of small lead ball, g = acceleration due to gravity = 9.8 m/s², r = length of rope = 1.10 m and ω = angular speed of lead ball = 3 rev/s = 3 × 2π rad/s = 6π rad/s = 18.85 rad/s and a = acceleration of normal force. So,
a = g + rω²
= 9.8 m/s² + 1.10 m × (18.85 rad/s)²
= 9.8 m/s² + 390.85 m/s²
= 400.65 m/s²
Now, using v² = u² + 2a(h₂ - h₁) where u = initial velocity of ball = rω = 1.10 m × 18.85 rad/s = 20.74 m/s, v = final velocity of ball at maximum height = 0 m/s (since the ball is stationary at maximum height), a = acceleration of small lead ball = -400.65 m/s² (negative since it is in the downward direction of the tension), h₁ = initial position of lead ball above the ground = 1.3 m and h₂ = final position of lead ball above the ground = unknown.
v² = u² + 2a(h₂ - h₁)
So, v² - u² = 2a(h₂ - h₁)
h₂ - h₁ = (v² - u²)/2a
h₂ = h₁ + (v² - u²)/2a
substituting the values of the variables into the equation, we have
h₂ = 1.3 m + ((0 m/s)² - (20.74 m/s)²)/2(-400.65 m/s²)
h₂ = 1.3 m + [-430.15 (m/s)²]/-801.3 m/s²
h₂ = 1.3 m + 0.54 m
h₂ = 1.84 m
is college football playoffs the best way to determine the national champion?
Answer:
No it is Not because win ratio is differs say Ohio only won 7 out of 7 games and e
was in the playoffs while Alabama won 11 out of 11 games so it is harder to win 11 out of 1a games and it is easier to win 7 out of 7
Explanation: would like brainliest but u don’t have to
When you graph displacement vs. time, velocity is represented by
A. the x-intercept of the graph
B. the y-intercept of the graph
C. the slope of the graph
D. the curve of the graph
On a sunny day, a family decided to take sail on a nearby lake. During sailing the wind applies a force of 25N north on the sails of the sailboat. The
water however exerts a force of 20 N east. If the total mass of both the sailboat and the crew (family on board) is 20kg, what is the magnutude and
direction of the acceleration produced?
Answer:
its n
Explanation:
The acceleration of the boat is obtained as 1.6 ms-2.
We have to obtain the resultant force acting on the boat in order to obtain the acceleration of the boat.
Resultant force on the boat = √(25)^2 + (20)^2 = √625 + 400 = 32 N
Now recall that from Newton's laws; F = ma
m= mass of the body
a = acceleration of the body
32 N = 20Kg × a
a = 32 N/20Kg
a = 1.6 ms-2
Learn more about force: https://brainly.com/question/1301963
Two rope tows operate on the same ski slope. Tow A with a heavier load pulls as fast as Tow B. Which does the most work? Which has the most power?
Answer:
tow a has the most power but tow b does the most work
Explanation:
Tow A with a heavier load pulls as fast as Tow B, Then A does The most work, and A also has more power.
What is power?It is defined as the Rate of work done or the ratio of work done and time.
If the amount of work(W) is down over a time interval of (t) then the power is given by,
P=W/t
Where W=is work done by a force is known as a product of force and distance.
t= time interval in s.
Force
F= force which is known as the rate of momentum.=mv/t
where m= mass of the body in kg.
v= velocity in m/s.
Here in the question, given that A pulls heavier weight than B that means A applied more force which results in more work.
When more work is done by A than by B then the power of an also greater than B because they move at the same velocity.
Hence, The Work done as well as the power of A is more.
To find more on work done click:
https://brainly.com/question/28172139
#SPJ3
please help me this is timed .
Find x if a = 3.0 m/s^2
Answer:
x = 50 N
Explanation:
Given that we have a net force, a mass, and acceleration, we can use the fundamental formula for force found in newton's second law which is F = m × a.
Given a mass of 150 kg, and an acceleration 3.0m/s². We can substitute these two values in our formula to calculate the magnitude of these forces or it's net force to identify the unknown force acting on our known force for this situation to work.
_______
F (Net force) = F2 (Second force which we are given) - F1 (First force) = m × a
m (mass which we are given) = 150 kg
a (acceleration which we are given) = 3.0m/s
________
So F = m × a → F2 - F1 = m × a →
500 - F1 = 150 × 3.0 → 500 - F1 = 450 →
-F1 = -50 → F1 = 50
A block weighing 9.3 N requires a force of 3.7 N to push it along at constant velocity. What is the coefficient of friction for the surface
Answer:
0.398
Explanation:
According to friction, the frictional force is directly proportional to the normal reaction
Ff = nR
Ff is the frictional force
n is the coefficient of friction
R is the reaction
Reaction is equal to the weight
R= W = 9.3N
Fm = Ff = 3.7N
Fm is the moving force
Get the coefficient of friction
n = Ff/R
n = 3.7/9.3
n = 0.398
Hence the coefficient of friction for the surface is 0.398
Scientists create models to better understand Earth. Which evidence has led scientists to conclude that there are different layers within Earth's interior?
A.analysis of seismic wave data
B.measurement of Earth's diameter
C.temperatures taken within each layer
D.rock samples taken from Earth's core
Answer:
it is A or D
Explanation:
Answer:
ANswer:A
Explanation:
The force f is given in terms of time t and displacement X by the equation F= Asin Bx +C sin dt. What is the dimension of D/B?
Answer:
Here's what I think,
A_Trigonometric_ratio (whatever)
The general form of sin/cos/tan(angle).
So here as in the general form the "whatever" is always an "angle" input which (may sound a bit unfair but) is a dimensionless quantity.
As mentioned in your question,
F= Asin(Bt) + C cos (Dy)
Dimentions of these terms will be same (by homogenity of dimensions).
So what we gotta do here is make Bt and Dy dimensionless for this whole equation to work.
According to your question t is time,
So to make Bt dimensionless,
B must be equal to inverse of time i.e T^(-1)
Using the same process on Dy, gives inverse of length i.e L^(-1)
So,
B= M^(0)L^(0)T^(-1)
D = M^(0)L^(-1)T^(0)
The dimension of D/B then will be M^(0)L^(-1)T^(1)
what is phase voltage of star connected three phase system in balanced loa is 240 the line voltage
Answer:
Explanation: the Star Connection, the similar ends (either start or finish) of the three windings are connected to a common point called star or neutral point. The three-line conductors run from the remaining three free terminals called line conductor
A hammer strikes a nail with a 10 N force for 0.01 seconds. Calculate the impulse of the hammer.
Answer:
0.1Ns
Explanation:
Impulse is the product of Force and time
Impulse = Force * Time
Given
Force = 10N
Time = 0.01s
Substitute into the formula
Impulse = 10 * 0.01
Impulse = 10 * 1/100
Impulse = 10/100
Impulse = 0.1Ns
hence the impulse of the hammer is 0.1Ns
All of the following are ways in which sports psychologists help athletes except __________.
A.
staying motivated
B.
managing fear of failure
C.
improving performance
D.
enhancing memory
Please select the best answer from the choices provided
A
B
C
D
Answer:
D-Enhancing memory
Explanation:
In a particular crash test, an automobile of mass 1577 kg collides with a wall and bounces back off the wall. The x components of the initial and final speeds of the automobile are 17 m/s and 1.5 m/s, respectively. If the collision lasts for 0.18 s, find the magnitude of the impulse due to the collision. Answer in units of kg · m/s.
Answer:
Ft=24,443.5 kgm/s
Explanation:
Step one
Given data
Mass of automobile m=1577kg
Initial Velocity u=17m/s
Final Velocity v=1.5m/s
Time t=0.18s
Step two
From the impulse and momentum equation
Ft=mΔv
Substitute
Ft=1577*(17-1.5)
Ft=1577*15.5
Ft=24,443.5 kgm/s
A cart's initial velocity is +3.0 meters per second. What is its final velocity after accelerating at a rate of 1.5 m/s2 for 8.0 seconds?
A. 36 m/s
B. 9 m/s
C. 72 m/s
D. 15 m/s
Answer:
V = 15m/s
Explanation:
Given the following data;
Initial velocity = 3m/s
Time = 8secs
Acceleration = 1.5m/s²
To find the final velocity, we would use the first equation of motion;
V = U + at
Substituting into the equation, we have
V = 3 + 1.5*8
V = 3 + 12
V = 15m/s
A 146N force is needed to pull a 350 N block across a horizontal surface at a constant speed by a rope making an angle of 50 degrees with the floor. Find the coefficient of friction.
Answer:
F = force
f = friction
u = coefficient of friction
R = normal reaction force
a = Acceleration
m = mass of block
g = gravity
f = uR
F = Ma
Say the block is moving to the right.
The 146N force thus acts to the right, and the friction force to the left, since it resists movement.
The 146N force acts to the right, but the horizontal component of it is 146 cos 50 = 93.84: So this is the force to the right.
Since F = uR and we're trying to find u, we need both F and R. R is easy to get since it is just m x g. This is in fact already given as the weight 350N. So R = 350.
The block is moving at a constant speed, so the force to the right must = the force to the left.
F = ma, so 93.84 - f = (350/g) x 0
This means f must be 93.84 also.
so we have f = uR,
93.84 = u x 350
so u = 0.268 or
0.27 to 2dp.
Hope you understand this.
Explanation:
The coefficient of friction is 0.26 if the 46N force is needed to pull a 350 N block across a horizontal surface at a constant speed by a rope making an angle of 50 degrees with the floor.
What is the friction force?It is a type of opposition force acting on the surface of the body that tries to oppose the motion of the body. its unit is Newton (N). Mathematically it is defined as the product of the coefficient of friction and normal reaction.
We know:
f = uR
Where f is the friction force and u is the coefficient of friction, R is the normal reaction force.
The horizontal component of 146N is:
F' = 146cos50°
F' = 93.84 N
Since F = mass×acceleration
Because the block is traveling at a constant speed, the right-hand force must equal the left-hand force.
F' = f = 93.84 N
93.84 = u x 350 (R = 350N)
u = 0.26
Thus, the coefficient of friction is 0.26 if the 46N force is needed to pull a 350 N block across a horizontal surface at a constant speed by a rope making an angle of 50 degrees with the floor.
Learn more about the friction force here:
https://brainly.com/question/1714663
#SPJ2
The resistance of a wire depends on its length i and on its cross sectional area A the resistance is
Answer:
The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area
Explanation:
what makes 97 of the water on earth unfit for drinking
Answer:
presence of salt in oceanic water makes 97 of the water on the earth unfit for drinking
An inductor is connected to a 120-V, 60-Hz supply. The current in the circuit is 2.4 A. What is the inductive reactance
Answer:
Inductive reactance is 50.00 ohms
Explanation:
Given the following data;
Voltage = 120v
Frequency = 60Hz
Current = 2.4 A
To find the inductive reactance;
Inductive reactance, XL = V/I
Where;
XL represents the inductive reactance. V represents the voltage. I represents the current.Substituting into the equation, we have;
XL = 120/2.4
XL = 50.00 ohms
A motorcycle moving 18.8 m/s has
57800 J of KE. What is its mass?
Answer:
m = 327.07 kg
Explanation:
Given that,
Kinetic energy of a motorcycle, E = 57800 J
Velocity of the motorcycle, v = 18.8 m/s
We need to find the mass of the motorcycle. The kinetic energy of an object is given by :
[tex]E=\dfrac{1}{2}mv^2[/tex]
m is mass
[tex]m=\dfrac{2E}{v^2}\\\\m=\dfrac{2\times 57800 }{(18.8)^2}\\\\m=327.07\ kg[/tex]
So, the mass of the motorcycle is 327.07 kg.
When the 5.0 kg cylinder fell 100 m, the final temperature of the water was °C and the change in temperature was °C.
When the 5.0 kg cylinder fell 500 m, the final temperature of the water was °C and the change in temperature was °C.
Answer:
26.17
1.17
30.86
5.86
Explanation:
said they were correct on my assignment
Two floors in a building are separated by 4.1 m. People move between the two floors on a set of stairs. (a) Determine the change in potential energy of a 3.0 kg backpack carried up the stairs. (b) Determine the change in potential energy of a person with weight 650 N that descends the stairs.
Answer:
a) The change in potential energy of a 3.0 kilograms backpack carried up the stairs.
b) The change in potential energy of a persona with weight 650 newtons that descends the stairs is -2665 joules.
Explanation:
Let consider the bottom of the first floor in a building as the zero reference ([tex]z = 0\,m[/tex]). The change in potential energy experimented by a particle ([tex]\Delta U_{g}[/tex]), measured in joules, is:
[tex]\Delta U_{g} = m\cdot g\cdot (z_{f}-z_{o})[/tex] (1)
Where:
[tex]m[/tex] - Mass, measured in kilograms.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]z_{o}[/tex], [tex]z_{f}[/tex] - Initial and final height with respect to zero reference, measured in meters.
Please notice that [tex]m\cdot g[/tex] is the weight of the particle, measured in newtons.
a) If we know that [tex]m = 3\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]z_{o} = 0\,m[/tex] and [tex]z_{f} = 4.1\,m[/tex], then the change in potential energy is:
[tex]\Delta U_{g} = (3\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (4.1\,m-0\,m)[/tex]
[tex]\Delta U_{g} = 120.626\,J[/tex]
The change in potential energy of a 3.0 kilograms backpack carried up the stairs.
b) If we know that [tex]m\cdot g = 650\,N[/tex], [tex]z_{o} = 4.1\,m[/tex] and [tex]z_{f} = 0\,m[/tex], then the change in potential energy is:
[tex]\Delta U_{g} = (650\,N)\cdot (0\,m-4.1\,m)[/tex]
[tex]\Delta U_{g} = -2665\,J[/tex]
The change in potential energy of a persona with weight 650 newtons that descends the stairs is -2665 joules.
Which is greater, the energy of one photon of orange light or the energy of one quantum ofradiation having a wavelength of 3.36 * 10^-9
The question is incomplete, here is the complete question:
Which is greater, the energy of one photon of orange light or the energy of one quantum of radiation having a wavelength of [tex]3.36\times 10^{-9}m[/tex]
Answer: The energy of one quantum of radiation having wavelength [tex]3.36\times 10^{-9}m[/tex] is greater than the energy of 1 photon of orange light.
Explanation:
To calculate the energy of one photon, we use the Planck's equation:
[tex]E=\frac{N_Ahc}{\lambda}[/tex]
where,
E = energy of radiation
[tex]N_A[/tex] = Avogadro's number = [tex]6.022\times 10^{23}mol^{-1}[/tex]
h = Planck's constant = [tex]6.626\times 10^{-34}Js[/tex]
c = speed of light = [tex]3\times 10^8 m/s[/tex]
[tex]\lambda}[/tex] = wavelength of radiation
For orange light:For 1 photon, the term [tex]N_A[/tex] does not appear
[tex]\lambda}[/tex] = 620 nm = [tex]620\times 10^{-9}m[/tex] (Conversion factor: [tex]1nm=10^{-9}m[/tex] )
Putting values in above equation, we get:
[tex]E=\frac{6.626\times 10^{-34}Js\times 3\times 10^8m/s}{620\times 10^{-9}m}\\\\E=3.206\times 10^{-19}J[/tex]
For one quantum of radiation:[tex]\lambda}[/tex] = [tex]3.36\times 10^{-9}m[/tex]
Putting values in above equation, we get:
[tex]E=\frac{6.022\times 10^{23}mol^{-1}\times 6.626\times 10^{-34}Js\times 3\times 10^8m/s}{3.36\times 10^{-9}m}\\\\E=3.56\times 10^{7}J/mol[/tex]
Hence, the energy of one quantum of radiation having wavelength [tex]3.36\times 10^{-9}m[/tex] is greater than the energy of 1 photon of orange light.
If you travel from Tucson to Argentina, you will see some different constellations in the night sky. true or false
Answer:
its true!!
Explanation: have a nice day !!
A 9.0 kg test rocket is fired vertically from Cape Canaveral. Its fuel gives it a kinetic energy of 1905 J by the time the rocket engine burns all of the fuel. What additional height will the rocket rise
Answer:
21.6m
Explanation:
Since the rocket engine burns all the fuel hence the kinetic energy will be converted to potential energy
Potential Energy = mass × acceleration due to gravity × height
Given
PE = 1905J
Mass = 9.0kg
Acceleration due to gravity =9.8m/s²
Required
Height h
Substitute into the formula
1905 = 9(9.8)h
1905 = 88.2h
h =1905/88.3
h = 21.6m
Hence the required height is 21.6m
A projectile is launched at an angle of 60° from the horizontal and at a velocity of
12.0 m/s. What is the horizontal velocity of the projectile? *
Answer:
60*12.0= 720 = v/60 * 12.0 squared which is 1,728
Explanation:
Horizontal velocity component: Vx = V * cos(α)
The horizontal velocity of the projectile is 6.0m/s
If a projectile is launched at an angle from the horizontal and at a velocity v, the horizontal velocity of the projectile is expressed as:
[tex]v_x =vcos \theta[/tex]
Given the following parameters
v = 12.0m/s
[tex]\theta=60^0[/tex]
Substitute the given parameters into the formula to have:
[tex]v_x=12.0cos60\\v_x=12.0(0.5)\\v_x=6.0m/s\\[/tex]
Hence the horizontal velocity of the projectile is 6.0m/s
Learn more here: https://brainly.com/question/23916021