a librarian pushes a 35kg box of books across the library floor. if the carpet resists with a friction force of 91N, what force must be applied by the librarian to accelerate the box at a rate of 0.50m/s
Answer:
F = 108.5 [N]
Explanation:
To solve this type of problem we must use Newton's second law, which tells us that the sum of forces must be equal to the product of mass by acceleration.
ΣF = m*a
where:
ΣF = sum of forces [N]
m = mass = 35 [kg]
a = acceleration = 0.5 [m/s²]
f = friction force [N]
F - f = m*a
F - 91 = (35*.5)
F = 91 + 17.5
F = 108.5 [N]
how does an air pump work
Answer:
When the piston is pulled up, air gets sucked into the pump through the inlet. The pump chamber depressurizes as it fills with air. When the piston is forced down, the air becomes compressed and closes the inlet. Then the air flows out from the outlet
Two bodies made of the same material have same external dimension and appearance, but one is compact solid and other is hollow. When they heated for the same temperature range, is the overall volume expansion the same or different? Explain.
Answer:
Different
Explanation:
The hollow one will expand even more making it have a larger volume then the solid one so they are different
different between si unit and derived unit
Answer:
There are seven base SI units corresponding to different parameters and are considered independent of each other. Derived units are derived from these 7 base units. Derived units are dependent on the base units and are not independent of each other. For example, let us derive the SI units for force. By Newtons Second Law of Motion, the force is same as the product of mass and acceleration of a body. that is, force = mass x acceleration. Also, acceleration is defined as the rate of change of velocity. And velocity is defined as the rate of change of displacement. Thus, force = mass x acceleration = mass x dv/dt = mass x dt2 Mass has SI units of kg, distance is measured in m and t has the SI unit of second. Thus, Sl unit of force is kg.m/s^2 (also known as Newton).
A) 750gm
11. Ifa rectangular solid box of aluminum is heated, which of the following is not true?
A) Its mass remains constant
Cits density increase
B) Its volume increase
Do none of the above
Given :
A rectangular solid box of aluminum is heated.
To Find :
Which of the following is not true.
A) Its mass remains constant
C) its density increase
B) Its volume increase
D) none of the above
Solution :
We know, when an object is heated it expands.
Objects expands means that the volume increases but mass remains same by conservation of mass.
Since mass remains constant and volume increases.
So, density will decrease.
Hence, this is the required solution.
A satellite of mass 1000kg is in a circular orbit around a planet. The centripetal acceleration of the satellite in its orbit is 5m/s^2. What is the gravitational force exerted on the satellite by the planet?
A. 0N
B. 200N
C. 5000N
D. 10000N
Answer: 5000N
Explanation:
The basic principle of a circular orbit is that Fg = m × ac, so as we have the mass and the centripetal acceleration (also called normal acceleration) we just have to operate. Fg = 1000kg × 5m/s² = 5000N
The gravitational force exerted on the satellite of mass 1000 kg moving in a circular orbit with a centripetal acceleration of 5 m/s² by the planet is 5000 N (option C).
The gravitational force exerted on the satellite by the planet will be equal to the planet's gravity, which is equal to the centripetal force, so:
[tex] F_{g} = F_{c} = ma_{c} [/tex]
Where:
m: is the mass of the satellite = 1000 kg
[tex]a_{c}[/tex]: is the centripetal acceleration = 5 m/s²
The, the force acting on the satellite is:
[tex] F_{c} = ma_{c} = 1000 kg*5 m/s^{2} = 5000 N [/tex]
Therefore, the gravitational force exerted on the satellite by the planet is 5000 N (option C).
Learn more here:
https://brainly.com/question/11332442?referrer=searchResultshttps://brainly.com/question/24783651?referrer=searchResultsI hope it helps you!
Four examples of second class levers
Answer:
they are :
Explanation:
wheelbarrow bottle opener an oarA fossil mammoth bone was found to contain 6.25% carbon-14 percent isotope and 93.75% nitrogen-14 daughter isotope. If the half-life of carbon-14 is 5700 years old, how old is the mammoth bone?
Answer:
The mammoth bone is 22726 years old.
Explanation:
We can find how hold is the mammoth bone using the decay equation:
[tex]N(t) = N_{0}*e^{-\lambda t}[/tex] (1)
Where:
N(t): is the quantity at time t = 6.25%N₀
N₀: is the initial quantity
λ: is the decay constant
First, we need to find λ:
[tex] \lambda = \frac{ln(2)}{t_{1/2}} = \frac{ln(2)}{5700 y} = 1.22 \cdot 10^{-4} y [/tex]
Now, by solving equation (1) for t we have:
[tex]t = \frac{ln(\frac{N(t)}{N_{0}})}{-\lambda} = \frac{ln(0.0625)}{-1.22 \cdot 10^{-4}} = 22726 y[/tex]
Therefore, the mammoth bone is 22726 years old.
I hope it helps you!
What is the potential energy of a rock that weighs 10.0 kg and is sitting on top of a hill 300 meters high?
The potential energy of a rock that weighs 10.0 kg and is sitting on top of a hill 300 meters high is 29400J
POTENTIAL ENERGY:
Potential energy refers to the energy due to the position of an object. It can be calculated by using the following formula:P.E = m.g.h
Where;
m = mass of the rock
g = gravitational force of Earth (9.8m/s²)
h = height (m)
According to this question, a rock weighs 10.0 kg and is sitting on top of a hill 300 meters high. The potential energy can be calculated as follows:P.E = 10 × 9.8 × 300
P.E = 29400J
Therefore, the potential energy of a rock that weighs 10.0 kg and is sitting on top of a hill 300 meters high is 29400J.Learn more: https://brainly.com/question/15613166?referrer=searchResults
Which statements accurately describe matter
What is the final speed of an object that starts from rest and accelerates uniformly at 3.0 meters per second2 over a distance of 6.0 meters? (1) 8.0 m/s (2) 6 m/s (3) 16 m/s (4) 64 m/s
Answer:
16 m/s sir
Explanation:
because i am in collage
What is the speed in kilometers per hour of a 27.78m/s baseball pitch?
Answer:
100.008 km/h
Explanation:
multiply the speed value by 3.6
diffrence uniform and non uniform
A man carries a load of mass 2.6kg from one end of a uniform pole 100cm long which has a mass 0.4kg. The pole rest on his shoulder at a point 60.0cm from the load and he holds it by the other end. What vertical force must be applied by his hand and what is the force on his shoulder?
Answer:
F = 39.2 N (hand force) and N = 68.6 N (shoulder force)
Explanation:
In this exercise we must use the rotational and translational equilibrium conditions, we have several forces: the weight (W) of the pole applied at its geometric center, the load (w1) at one end, the shoulder support (N) 60 cm from the load and hand force (F) at the other end of the pole
Let's set the reference system at the fit point of the shoulder
∑ τ = 0
We will assume that the counterclockwise turns are positive
w₁ 0.60 + W 0.1 + F₁ 0 - F 0.4 = 0
all distances are measured from the support of the man (x₀ = 0.60 m)
F = (w₁ 0.60 + W 0.1) / 0.4
F = (m₁ 0.6 + m 0.1) g / 0.4
let's calculate
F = (2.6 0.6 + 0.4 0.1) 9.8 / 0.4
F = 39.2 N
this is the force that the hand must exert to keep the system in balance
We apply the translational equilibrium condition
-w₁ -W + N - F = 0
N = w₁ + W + F
N = (m₁ + m) g + F
let's calculate
N = (2.6 + 0.4) 9.8 + 39.2
N = 68.6 N
How did Robert Whittaker change classification?
He created an organizational hierarchy.
He classified organisms as plants or animals.
He added the Phylum and Family levels.
He reorganized life into five kingdoms.
Answer:
d
Explanation:
Which of the following is NOT a way that a machine makes work easier to do?
A. Change the size of a force
B. Change the type of force
C. Change the direction of the force
D. Change distance a force acts
Answer:
c
Explanation:
ur changing the way it move not to make it easier
The direction of the force, has nothing to do with how the machine will work easier. The correct option is C
A machine is any devices that make work easier. An ideal machine takes in small effort to overcome large load.
Since work has to be done in a machine, and work is the product of force and perpendicular distance, for a machine to work easier, the work done will depend on size of the force applied, the type of force applied, and also, the magnitude of the distance involved.
The direction of the force, has nothing to do with how the machine will work easier. Therefore, the correct option is C
Learn more here : https://brainly.com/question/19546590
A whale travels 112 meters at 14 m/s How long does this take?
Answer:
8
Explanation:
112meters divided by 14
Why does a liquid thermometer work
The Moon has a radius of 1.7 × 106 m and a mass of 7.3 × 1022 kg. Find the gravitational field on the surface of the Moon.
Answer:
10.7*[tex]10^{6}[/tex]
Explanation:
HELP NEEDED ASAP I'M GIVING BRAINLIEST
1) Select the best answer from the choices below. Light has many properties of waves, but sometimes it also behaves like:
a
A photon
b
Polarized light
c
Ultraviolet rays
d
A stream of particles
2) What type of waves transmit signals in satellite communication?
a
Microwaves
b
X-rays
c
Gamma Rays
d
Radio Waves
3) Cell phones use digital signals to send and receive information. These digital signals travel as what kind of wave?
a
Gamma rays
b
X-rays
c
Microwaves
d
Radio waves
Answer:
1.
d . A stream of particles
2. D. Radiowave
3. Microwaves
Answer:
1.
d . A stream of particles
2. D. Radiowave
3. Microwaves
Explanation:
Which statement is correct about two objects that have gravitational force?
They have mass.
They move slowly.
They are round in shape.
They have high temperature.
Answer:
1 and 2
Explanation:
The formula itself has nothing to do with shape or temperature. The formula does have mass and the speed depends on the how great the mass/radius is.
Una barra de hierro cuya longitud inicial es de 2m se le incrementa su temperatura de 20 °C a 120 °C ¿Cuál es la longitud final de la barra? (considera que el coeficiente de dilatación del hierro) es 1,2 x 10-5 1/°C ( 3 puntos)
Answer:
1.9976 m
Explanation:
An iron bar whose initial length is 2m has its temperature increased from 20 ° C to 120 ° C. What is the final length of the bar? (consider that the coefficient of expansion of iron) is 1.2 x 10-5 1 / ° C (3 points)
Given that,
Initial length of an iron bar, [tex]L_0=2\ m[/tex]
The temperature increased from 20°C to 120°C
The coefficient of expansion of iron is [tex]1.2\times 10^{-5}\ /^{\circ} C[/tex]
We need to find the final length of the bar.
The linear expansion equation is given by :
[tex]\Delta L=\alpha L\Delta T[/tex]
Where [tex]\Delta L[/tex] is the change in length
[tex]\Delta L=1.2\times 10^{-5}\times 2\times (120-20)\\\\=0.0024\ m[/tex]
Also, [tex]\Delta L = L_o-L[/tex]
L is final length
[tex]0.0024= 2-L\\\\L=2-0.0024\\\\=1.9976\ m[/tex]
So, the final length of the bar is 1.9976 m
Which statements describe science? Check all that apply. It lacks a formal process. It involves observation. It involves experimentation. It is not updated often. It is supported by evidence
Answer:
It involves observation
It involves experimentation
It is supported by evidence
Explanation:
Science can be described as a system of knowledge based on the understanding of the natural world. The subject of science requires the scientific method - a chronological series of steps that have to be followed while trying to understand events in the natural world. These steps are:
observationformulation of hypothesistesting of the hypothesis by experimentationconclusion based on available evidence from the experimentHence, science involves observation, experimentation, and it is supported by evidence.
Answer:b. c. e
Explanation:
Question 2 of 10
Which of the following careers would physicists be least qualified to perform,
based on their training?
A. Nuclear engineer
B. Solar panel designer
C. Research lab manager
D. Gardener
Answer:
a and d
Explanation:
a because a nuclear engineer is more on explosions which links to chemistry and d because Gardner is irrelevant
A 10 V fan with a current of 2 A is turned on for 30 seconds. Calculate the energy transferred in joules,
Answer:
E = 600 J
Explanation:
Given that,
Voltage, V = 10 V
Current, I = 2 A
Time, t = 30 s
We need to find the energy transferred. Energy transferred is calculated as follows :
[tex]E=I^2Rt[/tex]
Ohm's law, V = IR, R = V/I
[tex]E=I^2\times \dfrac{V}{I}\times t\\\\E=IVt\\\\E=2\times 10\times 30\\\\E=600\ J[/tex]
So, 600 J of energy is transferred.
Answer:600J
Explanation:
I need help on this question
Answer:
at rest because time is passing and speed is still at 0
Explanation:
A dog chases a skateboarder travelling at 10.4m/s.The skateboarder speeds up with a constant acceleration for 39m over 3.3s. We want to find the acceleration of the skateboarder over the 3.3s time interval.
Answer:
The acceleration of the skateboarder over the 3.3s time interval is 3.15 m/s²
Explanation:
Acceleration can be described as the rate of change of velocity (as seen in the question). The formula to be used here to determine the acceleration is
Acceleration (in m/s²) = velocity (m/s) ÷ time (s)
Acceleration = 10.4 ÷ 3.3
Acceleration = 3.15 m/s²
Thus, the acceleration of the skateboarder over the 3.3s time interval is 3.15 m/s²
Which of the following is not a true statement about atomic bonds?
Answer:
Havent seen this one before but the explanation should help you out :)
Explanation:
There are only three atomic bonds.
Ionic bonding.
Covalent bonding.
Metallic bonding.
Why work and energy both have same unit? Give reasons?
Answer:
Explanation:
both have same unit because energy is defined as the ability to do work and work is the measure of transfer of energy when an objects moved from one place to another place so both are same thats why both have same units
Which quantities define momentum?
Answer:
velocity and mass
Explanation:
:) apek