Answer:
The coefficient of static friction between the crate and the floor is 0.41
Explanation:
Friction Force
When an object is moving and encounters friction in the air or rough surfaces, it loses acceleration and velocity because the friction force opposes motion.
The friction force when an object is moving on a horizontal surface is calculated by:
[tex]Fr=\mu N[/tex] [1]
Where [tex]\mu[/tex] is the coefficient of static or kinetics friction and N is the normal force.
If no forces other then the weight and the normal are acting upon the y-direction, then the weight and the normal are equal in magnitude:
N = W = m.g
The crate of m=20 Kg has a weight of:
W = 20*9.8
W = 196 N
The normal force is also N=196 N
We can find the coefficient of static friction by solving [1] for [tex]\mu[/tex]:
[tex]\displaystyle \mu=\frac{Fr}{N}[/tex]
The friction force is equal to the minimum force required to start moving the object on the floor, thus Fr=80 N and:
[tex]\displaystyle \mu=\frac{80}{196}[/tex]
[tex]\mu=0.41[/tex]
The coefficient of static friction between the crate and the floor is 0.41
Gravity affects atmospheric pressure true or false
Answer:
false
Explanation:
The tree branch in the preceding problem sags, and the child's feet rest on the ground. If the tension in the rope is reduced to 220 N, what is the value of the normal force being exerted on the child's feet?
The complete question is
A 45-kg child sits on a 3.2-kg tire swing. The tension on the rope is 470 N. The tree branch sags and the child's feet rest on the ground. If the tension in the rope is reduced to 220 N, what is the value of the normal force being exerted on the child's feet?
Answer:
Therefore the Normal force is being exerted on the child's feet is 252.36( 250N).
Explanation:
We are given
mass of child = 45kg
mass of the tire = 3.2kg
g = 9.8 m/s^2
We have the first case in which the tire is in swing so tension in that case will be which is the resultant force.
Fr = Resultant force
Ft = Tension force
Fg= Gravitational force
Fr = Fg + Ft
0 = -mg + Ft
Ft = mg
= (45+3.2)*9.8
= 48.2 * 9.8
Ft = 472.36N ( which is close to 470)
In the second case the child is in the rest position, The resultant force will be zero.
Fr = Ft + Fn + Fg ( Normal force is denoted by Fn )
0 = Ft + Fn + Fg
Fn = -Fg -Ft
Fn = mg -Ft
= 472.36 - 220
Fn = 252.36N ( close to 250N)
Therefore the Normal force being exerted on the child's feet will be 252.36N.
An electric current consists of moving
A) atoms
B) electrons
C) elements
D) molecules
A) atoms
B) electronsC) elements
D) molecules
A student named Bob is on a bike and the mass is 50 kg. The force causes the student to accelerate at 3 m/s to the power of 2. Calculate the net force that causes this acceleration.???
Answer:
150 N
Explanation:
Force is equal to mass times acceleration. 50 kg accelerating at a mass of 3m/3² is undergoing a force of 150 m/s², or 150 Newtons
1. What is diffraction?
2.Give an example of diffraction.
Answer: a process which a beam of light spread out as a result of the passing through a narrow aperture
Explanation:
Which of these games was a racing game?
A.
Centipede
B.
Pole Position
C.
Xevious
D.
Galaxian
E.
Space Invaders
Answer:
B.
pole position
The sound intensity level at a seat that is a distance of 2.00 meters from a rock concert stage is 120 dB. (a) Calculate the Intensity, I1 , of the sound in W/m2 at that position. (b) Calculate the sound level in dB at a seat that is 32 meters from the stage, given that the intensity decreases with the square of the distance from the source.
Answer:
[tex]1\ \text{W/m}^2[/tex]
[tex]0.0039\ \text{W/m}^2[/tex]
Explanation:
[tex]I_1[/tex] = Intensity of sound at 2 m away
Sound level = 120 dB
[tex]r_1[/tex] = 2 m
[tex]r_2[/tex] = 32 m
[tex]I_0[/tex] = Threshold of sound = [tex]10^{-12}\ \text{W/m}^2[/tex]
Sound level is given by
[tex]dB=10\log (\dfrac{I_1}{I_0})\\\Rightarrow I_1=10^{\dfrac{dB}{10}}I_0\\\Rightarrow I_1=10^{\dfrac{120}{10}}\times 10^{-12}\\\Rightarrow I_1=1\ \text{W/m}^2[/tex]
The intensity of sound at 2 m away is [tex]1\ \text{W/m}^2[/tex]
[tex]I_1=\dfrac{P}{4\pi r^2}[/tex]
[tex]I\propto \dfrac{1}{r^2}[/tex]
[tex]\dfrac{I_1}{I_2}=\dfrac{r_2^2}{r_1^2}\\\Rightarrow I_2=\dfrac{I_1r_1^2}{r_2^2}\\\Rightarrow I_2=\dfrac{1\times 2^2}{32^2}\\\Rightarrow I_2=0.0039\ \text{W/m}^2[/tex]
The intensity of the sound 32 m away is [tex]0.0039\ \text{W/m}^2[/tex]
A baseball on the Moon and an identical baseball on the Earth are thrown vertically upward with the same initial velocity of 12 m/s. The acceleration due to gravity on the Moon is 1/6 that of Earth. What is the maximum height the ball reaches on the moon? What is the maximum height the ball reaches on the earth? What is the difference in the maximum height the ball reaches on the Moon compared to on Earth?
Answer:
a. 3.68 m b. 0.61 m c. 3.07 m
Explanation:
a. What is the maximum height the ball reaches on the moon?
Using v² = u² - 2g'h where u = initial velocity of baseball = 12 m/s, v = final velocity of baseball = 0 m/s (since it stops at maximum height), g' = acceleration due to gravity on moon = g/6 where g = acceleration due to gravity on earth = 9.8 m/s², so g' = 9.8 m/s²/6 = 1.63 m/s² and h = maximum height of ball on moon.
So, making h subject of the formula, we have
h = -(v² - u²)/2g'
substituting the values of the variables, we have
h = -((0 m/s)² - (12 m/s)²)/2(1.63 m/s²)
= -(- 12 m²/s²)/2(1.63 m/s²)
= 6 m²/s²)/(1.63 m/s²)
= 3.68 m
b. What is the maximum height the ball reaches on the earth?
Using the same equation for the maximum height the baseball travels on the moon for that on the earth, the maximum height h' the baseball travels on the earth is given by
h' = -(v² - u²)/2g where u = initial velocity of baseball = 12 m/s, v = final velocity of baseball = 0 m/s (since it stops at maximum height), g = acceleration due to gravity on earth = 9.8 m/s²and h' = maximum height of ball on moon.
substituting the values of the variables, we have
h = -((0 m/s)² - (12 m/s)²)/2(9.8 m/s²)
= -(- 12 m²/s²)/2(9.8 m/s²)
= 6 m²/s²)/(9.8 m/s²)
= 0.61 m
c. What is the difference in the maximum height the ball reaches on the Moon compared to on Earth?
The difference in the maximum height the ball reaches on the Moon compared to on Earth is d = h - h' = 3.68 m - 0.61 m = 3.07 m
All of the following use an electric motor, EXCEPT
A.) radio
B.) blender
C.) hair dryer
D.) electric fan
Answer:
radio
Explanation:
Answer:
radio
Explanation:
all except radio use electric motors
which object is completely opaque?
a:wooden spoon
b: drinking glass
c: wax paper
d:window
Answer:
a
Explanation:
light can not pass through it completely
Light that enters your eye strikes cells in the back of your eye
true
False
Answer: True
Explanation: Light enters your eye through the lens which then hits the retina which is located in the back of your eye.
Can someone help me out?
Answer:
B). Rarefaction :) _____
the arrow points to the rarefactions
A person pours some chlorine bleach into a clothes washer to remove stains from the clothing. What is one chemical property or the bleach?
A. It’s density
B. It’s mass
C. It’s color
D. It’s pH
One chemical property of the bleach is its pH.
What is pH?This is referred to as the power of hydrogen and is a measure of how acidic/basic a substance is.
pH is an example of chemical property because it's associated with a change in its chemical composition. This thereby makes option D the most appropriate choice.
Read more about pH here https://brainly.com/question/4137247
Answer: It's pH
Explanation: I took the test
The acceleration due to gravity on the earths surface is?
Acceleration due to gravity depends directly on the mass of Earth and inversely to the square of radius of Earth.
Answer:
9.8 m/s2
Explanation:
Acceleration due to gravity is the acceleration gained by an object due to the gravitational force. Its SI unit is m/s 2. It has both magnitude and direction, hence, it’s a vector quantity. Acceleration due to gravity is represented by g. The standard value of g on the surface of the earth at sea level is 9.8 m/s2.
A sledge is pulled in a straight line by dogs, as shown. The dogs produce a total horizontal driving force of 600 N. The frictional force between the sledge and the surface is 150 N and the air resistance on the sledge is 450 N. What is the resultant force acting on the sledge
Answer:
F = 0 N
Explanation:
The direction of air resistance and frictional force will be same and opposite to the direction of the driving fore of dogs. Therefore, the resultant force can be given as follows:
[tex]resultant\ Force = F = Driving\ Force\ of\ Dogs - Frictional\ Force - Air\ Resistive\ Force[/tex]here,
driving force of dogs = 600 N
Frictional Force = 150 N
Resultant Force = 450 N
Therefore,
[tex]F = 600\ N - 150\ N- 450\ N[/tex]
F = 0 N
_______________ is the name for the permanent destruction and clearing of forests
Answer:
DeforestationExplanation:
__________________________________________________________
According to Vocal Media,
__________________________________________________________
Deforestation is the permanent destruction of forests in order to utilize the land or trees. Typically, deforestation is clearing a lot of trees without the intention of establishing future growth. Harvesting, forest fires, and insect infestations do not count as deforestation because the affected areas will eventually grow back.
__________________________________________________________
Hope this helps! <3
__________________________________________________________
A soccer player kicks a ball 6.5 meters. How much time is needed for the ball to travel this distance if its velocity is 22 meters per second?
. . .
. . .
. . .
!
.
Your answer is 0.30 seconds
Chapter 5 Review Questions
How would you calculate the spring constant of an unknown spring?
A. graph the force vs. extension of the spring and find the slope
B. Use Hooke's law to calculate the spring constant knowing one force of the spring and one deformation of the spring
C. graph the force vs. extension of the spring and find the inverse of the slope
D. conduct a series of experiments with different amounts of deformation on the spring and calculate spring constant with Hooke's Law
Janet jumps horizontally off a high diving platform with a velocity of 2.76 m/s and lands in the water 2.3 s later. How high is the platform? The acceleration of gravity is 9.8 m/s. Answer in units of m.
How far from the base of the platform does she land? Answer and units of m.
Answer:
(a) Let the height of the platform is h meter,
=>By s = ut + 1/2gt^2
=>h = 0 + 1/2 x 9.8 x (2.3)^2
=>h = 25.92 m
(b) By R = [Ux] x t
=>R = 2.47 x 2.3
=>R = 5.68 m
Explanation:
Explanation:
From the exercise we know the initial horizontal velocity and the time that Janet takes to land in the water
a) Knowing the formula for free falling objects, we can calculate how high is the platform
At t=2.3m the position of Janet is y=0m
So, the platform is 26m tall
b) According to dynamics the displacement of an object can be analyze using the following formula:
So, Janet lands 6 m far from the base of the platform
Applying the Law of Conservation of Energy. If a car was released down the track from a height what happens to the potential energy and Kinetic energy as the car goes down the ramp?
Answer:
According to the law of conservation of energy, energy cannot be created or destroyed, although it can be changed from one form to another. KE + PE = constant. A simple example involves a stationary car at the top of a hill. As the car coasts down the hill, it moves faster and so it’s kinetic energy increases and it’s potential energy decreases. On the way back up the hill, the car converts kinetic energy to potential energy. In the absence of friction, the car should end up at the same height as it started.
This law had to be combined with the law of conservation of mass when it was determined that mass can be inter-converted with energy.
One can also imagine the energy transformation in a pendulum. When the ball is at the top of its swing, all of the pendulum’s energy is potential energy. When the ball is at the bottom of its swing, all of the pendulum’s energy is kinetic energy. The total energy of the ball stays the same but is continuously exchanged between kinetic and potential forms
HELP ASAP
The Target employees are working hard to get the orders out to everyone. The employees need to move packages from the ground level to the top of the loading dock platform. As shown in Figure 1, the employee pushes the package up a ramp (you may assume friction is negligible). In figure 2, the employee lifts the package straight up from ground to the loading dock platform. In which case does the employee do more work on the box and why?
a
Lifting the box straight up, because the incline acts as a simple machine and reduces the force required
b
Lifting the box straight up, because it requires a larger applied force to lift it straight up
c
Pushing the box up the incline, because the force is applied for a longer distance
d
Neither method, because the work is the same in both cases, since using the ramp decreases the force by the same factor that it increases the distance
Answer:
I believe the answer is B
Two ice skaters are at rest and facing each other. In order to move, they push
off each other. What is known about their final total momentum?
A. One skater must remain at rest.
B. Nothing is known about the final total momentum.
C. The final total momentum must equal zero.
D. Since they are on ice, this will not work. Neither can move.
Answer:
A
Explanation:
Hopefully this helps
Two ice skaters are at rest and facing each other. In order to move, they push off each other, then their net final total momentum must equal zero, therefore the correct answer is option C.
What is momentum?
It can be defined as the product of the mass and the speed of the particle, it represents the combined effect of mass and the speed of any particle, and the momentum of any particle is expressed in Kg m/s unit.
As given in the problem statement two ice skaters are at rest and facing each other. In order to move, they push off each other,
By using the conservation of the momentum,
The initial total momentum of two skaters = the final total momentum of the skaters
Since, initially, they are at rest and their initial total momentum is zero therefore the correct answer is option B
To learn more about momentum from here, refer to the link;
brainly.com/question/17662202
#SPJ5
An 80.0 kg fisherman jumps into a 37.5kg boat that is at rest. If the velocity of the fisherman is 5.60m/s when he jumps from the dock, what will be the velocity of the boat and fisherman after he lands in the boat?
Answer:
The velocity of the boat and fisherman after he lands in the boat is 3.812m/s
Explanation:
We will solve this question on the general Derivation for general case of a man jumping n the boat
m = Mass of the man = 80kg
M= mass of the boat 37.5kg
V(m, g) = Velocity of man with respect to ground = 5.6m/s
V(b , g) = Velocity of boat with respect to ground = Vo = 0m/s ( rest)
velocity of the boat and fisherman after he lands in the boat = V1
As there is no external force acting on the man then we can apply conservation of the Linear Momentum.
m*V(m, g) + M*Vo = (M+m)V1
[tex]V1 = \frac{ m*V(m, g) + M*Vo}{M+m}[/tex]
On substituting the values we get
V1 = [tex]\frac{80*5.6 + 37.5*0}{80+ 37.5}[/tex]
V1 = [tex]\frac{448}{117.5}[/tex] = 3.812 m/s
Therefore the velocity of the boat and fisherman after he lands in the boat is 3.812m/s.
If the person's velocity is changing is the person
accelerating
Answer:
a change in velocity can be a change in magnitude (or speed), but it can also be a change in direction.
Which is the correct equation for the force applied by a spring?
Answer:
B. [tex]F = -k*x[/tex]
Explanation:
The force of a spring can be easily calculated using Hooke's law which tells us that the force applied on a spring is equal to the product of the constant of a spring by the compressed or stretched distance of the spring.
That is:
[tex]F = k*x[/tex]
k = spring constant [N/m]
x = distance [m]
Chloe leads South’s varsity softball team in hitting. In a game against New Greer Academy this past weekend, Chloe slugged the 1-kg softball so hard that it cleared the outfield fence and landed on Lake Avenue. At one point in its trajectory, the ball was 19.2 m above the ground and moving with a speed of 31.6 m/s. Determine the total mechanical energy of the softball.
Answer:
it has the same mechanicals as a baseball
Explanation:
A power plant to represent the need for and use for energy; label it energy production.
Which of these is not a method of preventing the corrosion of metals?
A) galvanising
B) painting
C) plating
D) rusting
Answer:
D
Explanation:
rusting is actually the corrosion of metals so it can't be a way to prevent itself.
4. If you fall out of a plane and point your head down, it would take about 5 s to
reach a velocity of 49.1 m/s downward. What is the acceleration of gravity?
Answer:
acceleration due to gravity is always going to be 9.8m/s^2 whenever an object is freely falling.
Explanation:
You could also divide 49.1 m/s by 5s to get an acceleration of 9.8 m/s^2 as well.
how many cups are in 4 gallons
Answer:
there are 64 cups
Explanation:
remember this: two cups in a pint, two pints in a quart, two pints in a quart, four quarts in a gallonl2
