A 70 kg box undergoes a horizontal acceleration of 3.0 m/s^2 on a level surface when pulled by a 130 N force, What is the coefficient of kinetic friction between the box and the surface?
I think there's a typo in the question...
Vertically, the box is in equilibrium, so its weight and the normal force (magnitudes w and n, respectively) are such that
n + (-w) = 0
The box has mass 70 kg, and assuming gravitational acceleration with magnitude g = 9.80 m/s², it has a weight of
w = (70 kg) g = 686 N
and hence
n = 686 N
Horizontally, the box is accelerated 3.0 m/s², so the net force acting on it is
∑ F = (70 kg) (3.0 m/s²) = 210 N
and the only forces acting in this dimension are the pulling force with magnitude 130 N and the friction force with magnitude f so that
130 N - f = 210 N
The friction force is proportional to the normal force by a factor of µ, the coefficient of kinetic friction, so that
f = µ n
and so we have
130 N - µ (686 N) = 210 N → µ ≈ -0.117
but µ can't be negative!
The problem is that the pulling force should have a magnitude larger than that of the net force, so either the given mass, acceleration, or pulling force are incorrect.
pls help me this is being timed. pls.
Answer:
10N each
Explanation:
Doing a little math here to make it balanced. 10+10=20 therefore you have the same on both sides.
Hope this helps!
a measuring cylinder contains 30cm3 of a liquid some more of the liquid is added until the liquid level reaches the 50cm3 mark the reading on the balance increases by 30g what is the density of liquid?
Answer:
1.5g/cm³
Explanation:
Given parameters:
Initial volume of the liquid = 30cm³
Final volume of the liquid = 50cm³
Mass of the liquid = 30g
Unknown:
Density of the liquid = ?
Solution:
Density is the mass per unit volume of a substance.
Density = [tex]\frac{mass}{volume}[/tex]
volume of the liquid = final volume - initial volume = 50cm³ - 30cm³
volume of the liquid = 20cm³
Density = [tex]\frac{30}{20}[/tex] = 1.5g/cm³
1. In the context of the poem, what does it mean to feel alone? How can two people experience isolation despite living in the same home and being in the same relationship? What effect does one’s expectations of a relationship have on feelings of isolation?
hello
Explanation:
I haven't read the poem because you didn't attach it but here is my go at answering the question- although we find it hard to imagine being lonely while with others... if you lack emotional or intellectual connection even being physically near someone you are not mentally there
what do electrons move from
Answer:
Negatively charged, to positively charged parts
Explanation:
Electrons are negative, negative is attracted to positive.
A 20kg block is sliding down a 30° ramp at a constant velocity. Calculate the normal force acting on the block. Calculate the coefficient of kinetic friction between the block and the ramp.
Let me try:
Normal force= 169.74N
Coefficient of kinetic friction= 0.577
Explanation
a. For a given inclined plane, normal friction is equal to the force perpendicular to the plane which is equal to
mgcos theta = 20×9.8× cos30 = 169.74N
b. The coefficient of kinetic friction for an inclined plane is given as
tan theta =tan 30 = 0.577
What are gears and what is a lever ?
Answer:
agear lever or agear stick is the lever that you use to change gear in acar or other vehicle
ANSWER EVERYTHINGG PLEASE
Un ciclista A marcha a 24 Km/h y un ciclista B se desplaza a 6,8 m/s, Ambos están ubicados en un camino que tiene 4 Km de largo, pero el ciclista A está ubicado en el inicio del camino y el ciclista B está a 500 metros después. Conteste: a) Cuál de los dos ciclistas se desplaza a mayor velocidad b) Cuánto tiempo demora cada ciclista en llegar al extremo final del camino
Answer:
(a) Cyclist A travels faster.
(b) The time taken by cyclists A and B is 10 minutes and 8.58 minutes respectively.
Explanation:
Given that the speed of cyclist A= 24 km/h
As 1 km = 1000 m and 1 hour= 3600 seconds.
So, [tex]24 \frac {km}{h}=24\times \frac{1000 m}{3600 s}=\frac{20}{3}\frac {m}{s}=6.67 m/s[/tex]
and the speed of cyclist B = 6.8 m/s.
The length of the road = 4 km=4000 m.
(a) Speed of cyclist A is 6.67 m/s which is more than the 6.8 m/s.
Hence, cyclist A travels faster.
(b) If d be the distance to be traveled and V be the speed, than the time, t, required is,
[tex]t=\frac{d}{V}\cdots(i)[/tex]
For cyclist A:
As A is located at the beginning of the road, he has to cover full length of the road.
So, the distance to be covered by cyclist A =4 km.
Hence, from equation (i), the time taken by cyclist A is
[tex]t=\frac{4}{24}=\frac{1}{6}[/tex] hour
[tex]=\frac{1}{6}\times {60}=10[/tex] minutes. [ as 1 hour = 60 minumes]
So, time taken by cyclist A is 10 minutes.
For cyclist B:
As B is located 500 meters later from the beginning of the road, he has to cover the remaining length of the road.
So, the distance to be covered by cyclist B =4000 m-500 m= 3500 m.
Hence, from equation (i), the time taken by cyclist B is
[tex]t=\frac{3500}{6.8}=514.71[/tex] seconds
As 60 seconds= 1 minute.
So, t= 514.71/60 minutes = 8.58 minutes.
[tex]=\frac{1}{6}\times {60}=10[/tex] minutes. [ as 1 hour = 60 minumes]
So, the time taken by cyclist B is 8.58 minutes.
What is the velocity of galaxy mice
Explanation:
Both galaxies show bicones of high ionisation gas extending along their minor axes. In NGC 4676A the high gas velocity .
please. follow. me
If two negatively charged small sphere, one with twice the charge of the other, are 18cm a part in air. Calculate the charge on each if the force exerted by each on the other is 0.00081?
Answer:
q₂ = 3.81 x 10⁻⁸ C = 38.1 nC
q₁ = 7.63 x 10⁻⁸ C = 76.3 nC
Explanation:
The force between two charges is given by Coulomb's:
F = kq₁q₂/r²
where,
F = Force = 0.00081 N
k = Coulomb's Constant = 9 x 10⁹ Nm²/C²
q₁ = magnitude of 1st charge
q₂ = magnitude of second charge
r = distance between charges = 18 cm = 0.18 m
Therefore,
0.00081 N = (9 x 10⁹ Nm²/C²)q₁q₂/(0.18 m)²
q₁q₂ = (0.00081 N)(0.18 m)²/(9 x 10⁹ Nm²/C²)
q₁q₂ = 2.916 x 10⁻¹⁵ C²
q₁ = 2.916 x 10⁻¹⁵ C²/q₂ --------------- equation (1)
It is given that:
q₁ = 2q₂ --------------- equation (2)
Comparing equation (1) and equation (2):
2q₂ = 2.916 x 10⁻¹⁵ C²/q₂
q₂² = 2.916 x 10⁻¹⁵ C²/2
q₂ = √14.58 x 10⁻¹⁶ C²
q₂ = 3.81 x 10⁻⁸ C = 38.1 nC
using this value in equation (2):
q₁= 2(3.81 x 10⁻⁸ C)
q₁ = 7.63 x 10⁻⁸ C = 76.3 nC
A 1250 kg Nascar is at the starting line. The race starts and the car reaches a speed of 30
m/s in 10 seconds. What is the force of the car? (Hint: Remember that acceleration
change in velocity / time.)
Answer:
force=1250kg * 30m/s+10
Explanation: it's a change in acceleration
Which is unnecessary to include when accurately drawing ray diagrams?
focal point
lens
focal length
three easy rays
Answer:
Focal length
Explanation: No need for one...
Focal length is unnecessary to include when accurately drawing ray diagrams.
What is Focal length?The focal length is the distance, in millimeters, between the lens' optical center and the camera sensor, which records light data.
The elements inside the housing of a lens bend and shape light as it enters the front so that it converges into a single point of focus known as the "optical center."
It is crucial to remember that this measurement is made with the camera set to infinity and that lenses are named according to their focal length, which is indicated on the lens' barrel.
Therefore, Focal length is unnecessary to include when accurately drawing ray diagrams.
To learn more about Focal length, refer to the link:
https://brainly.com/question/23276372
#SPJ6
How do you think weather can increase the demand for electricity?
Someone help me! it's 1:23am were i live and i feel like my brain is going to implode
Answer:
Extreme temperatures can increase demand for heating and cooling, and the resulting increases in electricity demand can push up fuel and electricity prices.
Explanation:
How do you calculate the potential energy by it's height and weight? and is there any other way to solve it?
Answer:
PE = mgh
Explanation:
m is mass, g is gravitational constant (9.81) and h is height
Velocity is different from speed because it has both size and... what?
Velocity is size and direction
3 difference between weather and climate
weather is everyday things
weather could be a hurricane
weather could be a tornado
climate is more long term over time
example the climate in Antarctica is cold because it happens over long periods overtime
PLEASE HELPPPP You have a oxygen atom that is looking to bond. How many atoms of one element from column 1 would need to bond with that oxygen to form an ionic bond? Why?
Answer:
Two atoms from column 1. Each would give 1 electron to the Oxygen. Oxygen will be 2- and each group 1 ion will be 1+
Explanation:
Sorry if Im wrong
With Christmas lights wired in series, if one light goes out, what happens to the rest?
Answer:
The ones that are after the light that went out are also out.
Explanation:
Answer:
they all go out
Explanation:
they are wired together so they all go out. i am an electrician.
Which of the following is an example of a luminous object?
Dog
Tree
Candle
Moon
Answer:
Candle
Explanation:
The moon is an illuminated object, while a candle is a luminous object!
Answer:
Candle
Explanation:
I just took the test
A car, initially traveling at 5 meters per second north, accelerates to 25 meters per second north in 4.0 seconds. Determine the magnitude and direction of the car's acceleration.
Answer:
a = 5 [m/s²]
Explanation:
To solve this equation we must use the following equation of kinematics.
[tex]v_{f} =v_{o} +a*t[/tex]
where:
Vf = final velocity = 25 [m/s]
Vo = initial velocity = 5 [m/s]
a = acceleration [m/s²]
t = time = 4 [s]
Note: The positive sign for the acceleration in the above equation means that the car is increasing its velocity.
25 = 5 +a*(4)
25 - 5 = 4*a
20 = 4*a
a = 5 [m/s²]
How does wheel and axle work ?
Answer:
This system uses angular momentum and torque to do work on objects, typically against the force of gravity. The wheel and axle simple machine is closely related to gears.
Describe how reactivity changes as you go down Group 1A.
Answer:
it is a the answer is a btw
Explanation:
Physical activity increases your risk for coronary artery disease. true false
Answer:
false here is why :)
Explanation:
Regular, moderate-intensity physical activity reduces the risk of developing coronary heart disease and can reduce the likelihood of dying from heart disease.
hope this helped.
The whale shark is the largest of all fish and can have the mass of three adult
elephants. Suppose that a crane is lifting a whale shark into a tank for delivery
to an aquarium. The crane must exert an unbalanced force of 2.5 x 104 N to
lift the shark from rest. If the shark's acceleration while being lifted equals
1.25 m/s², what is the shark's mass?
Answer:
m = 20,000 kg
Explanation:
Force, [tex]F=2.5\times 10^4\ N[/tex]
Acceleration of the shark, [tex]a=1.25\ m/s^2[/tex]
It is required to find the mass of the shark. Let m is the mass. Using second law of motion to find it as follows :
F = ma
Putting the value of F and a to find m
[tex]m=\dfrac{F}{a}\\\\m=\dfrac{2.5\times 10^4}{1.25}\\\\m=20,000\ kg[/tex]
So, the shark's mass is 20,000 kg.
A 15 kg object has a momentum of 150 kg-m/s north. What is the object's
velocity?
O A. 135 m/s
O B. 2,250 m/s
O C. 0.1 m/s
O D. 10 m/s
Answer:
10 m/s
Explanation:
divide 150 by 15
Answer:
[tex]\boxed {\boxed {\sf D. \ 10 \ m/s}}[/tex]
Explanation:
Momentum can be found by multiplying mass by velocity.
[tex]p=mv[/tex]
If we rearrange this formula for velocity (v), then the formula becomes:
[tex]\frac{p}{m}=\frac{mv}{m}[/tex]
[tex]\frac{p}{m} =v[/tex]
We have to divide the momentum by the mass. The momentum is 150 kg*m/s and the mass is 15 kilograms.
[tex]p=150 \ kg*m/s\\m=15 \ kg[/tex]
Substitute the values into the formula.
[tex]\frac{150 \ kg *m/s}{15 \ kg} =v[/tex]
Divide. Note that the kilograms (kg) will cancel each other out.
[tex]10 \ m/s=v[/tex]
The velocity of the object is 10 meters per second.
What is a super dense gravitationally collapsed mass from which no light
can escape called?
1) neutron star
2) pulsar
3) supernova
4) black hole
A student wishes to conduct an investigation on heat transfer that demonstrates convection, Which
method should the student use?
A.
Pour hot, colored water into a bowl of cooler water that is another color,
B.
Melt chocolate bars in a microwave at different settings,
C.
Leave a glass of ice water outside in the direct sunshine.
D.
Place a spoon that is room temperature on top of a hot burner on a stove,
A football is thrown with a horizontal velocity of 15.0 m/s and a vertical velocity of 4.25m/s. What is the football's velocity?
what is the net force
Answer:
20 N in West direction.
Explanation:
opposite forces cancel each other. so 20 N in north and 20N in south cancel each other. In west and east direction...
70N in west-50N in east= 20N in west
