1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
marysya [2.9K]
4 years ago
9

ANswer the question and give example: Can friction ever perform positive work?

Physics
2 answers:
Harman [31]4 years ago
4 0
Yes. Think of block sitting on top of a bigger block. If the bottom block moves, it will drag the top block with it. Since the force of friction on the small block and its displacement are in the same direction, the "work" is positive. The static friction is a passive force, It is not a source of energy; it transmits the force placed on the bottom block. (And the "work" done by the friction on the bottom block is exactly the negative of the work done on the top block.) 
quester [9]4 years ago
3 0
It do both Positive and Negative work.
If we have to stop some object then friction does a positive work.
For Example: to stop a car , necassary friction is required between the tyres of car and road to stop a car . 

You might be interested in
Nepal has high potential for producing hydroelectricity however it is difficult too.
Stels [109]

Answer:

I'm not a scholar of hydroelectric power in Nepal, so consider my answers carefully, below.

Explanation:

High Potential:  Hydroelectric power comes from the potential energy stored in a mass that is above Earth's surface.  As the word "hydro" implies, the mass in this case is water.  Water from snow and glacier melt, and from normal precipitation (rain) in mountainous regions eventually cascades down the mountains in fast-flowing rivers or waterfalls.  Often, there are lakes or man-made reservoirs to collect and store the water before it flows down.  Mt. Everest is 8848 meters tall (about 29,000 feet).    If a lake forms at just 2,000 meters, one can calculate the amount of energy in each kilogram of water stored in the lake that represents the potential energy available at that altitude.  1 kg of water at 2,000 meters has potential energy, PE, according to the equation:  PE = mgh, where m is the mass in kg, g is Earth's acceleration due to gravity (9.8 m/sec^2), and h is height, in meters.  

PE = mGH

PE = (1 kg)*(9.8 m/sec^2)*(2,000 meters) = 19,000 kg*m/sec^2

1 kg*m/sec^2 is the SI unit for 1 Joule, a measure of energy.

This potential energy can be converted into electrical energy by releasing the water so that it can flow down to a water-powered turbine that spins magnets and coils of wire that produce electricity.  The 19,000 Joules of water potential energy can be converted to electrical power, less any inefficiency in the system, such as friction.

Nepal has the natural advantage in that it has many high mountain ranges with water flows that can be used for generating electrical power.  The result is low operating costs (the fuel is the flowing water) and no greenhouse gas emissions

The difficulty in developing hydroelectric power in Nepal is due to the same factor that gives it an advantage:  it is difficult constructing large hydroelectric plants in such rough terrain, and the power lines that are needed to transport the power to its destination are expensive and difficult to maintain and repair.

8 0
2 years ago
In which state of matter are particles held together but still able to move around
Aloiza [94]
The answer is B because the water molecules
5 0
3 years ago
Read 2 more answers
A 2 kg ball is moving 3 m/s when it starts rolling up a hill.
AURORKA [14]

Answer:

the height reached is = 0.458 [m]

Explanation:

We need to make a sketch of the ball and see the location of the reference point where the potential energy is zero. But the kinetic energy will be defined by the following expression:

Ek=\frac{1}{2} *m*v^{2} \\where:Ek= kinetic energy [J]\\m = mass of the ball [kg]\\v = velocity of the ball [m/s]

Replacing the values on the equation we have:

Ek=\frac{1}{2}*(2)*(3^{2} )\\ Ek=9[J]\\

This kinetic energy will be transformed in potential energy in the moment when the ball starts to rolling up. Therefore the maximum height reached by the ball depends of the initial velocity given to the ball.

Ek=Ep\\where\\Ep=potential energy [J]\\Ep=m*g*h\\where\\g=gravity = 9.81[m/s^2]\\h=height reached [m]\\

Now we have:

h=\frac{Ep}{m*g} \\h=\frac{9}{2*9.81} \\\\h=0.45 [m]

In that moment when the ball reach the 0.45 [m] the potencial energy will be maximum and equal to the kinetic energy when the ball has a velocity of 3[m/s]

6 0
3 years ago
What is the smallest possible piece an element in broken down into my normal laboratory processes
lozanna [386]

answer would be: A. atom

8 0
3 years ago
5. A 1.2 m guitar string is under a tension of 888 N. The waves produced on the string (when
Usimov [2.4K]
I don’t even know tbh
4 0
3 years ago
Other questions:
  • While planets are smaller than stars, planets are generally larger than which of the following?
    15·2 answers
  • A total charge of 6.3×10−8 C is distributed uniformly throughout a 2.7-cm radius sphere. The
    13·2 answers
  • Aleksei’s family purchased a new water heater that is a heat pump. After installation, Aleksei noticed that the room containing
    10·2 answers
  • .A 0.2-kg aluminum plate, initially at 20°C, slides down a 15-m-long surface, inclined at a 30 angle to the horizontal. The forc
    14·1 answer
  • A rigid vessel of 0.06 m3 volume contains an ideal gas , CV =2.5R, at 500K and 1 bar.a). if 15000J heat is transferred to the ga
    14·1 answer
  • An object is thrown with a horizontal velocity of 20 m/s from a cliff that is 125 m above level ground. If air resistance is neg
    5·1 answer
  • Determine whether the interference is constructive or destructive at each location indicated.
    15·1 answer
  • Which mineral is also an element graphite courts calcite hematite
    13·1 answer
  • In the laboratory you will find three bottles with the following labels:
    12·1 answer
  • A basketball is thrown with an initial upward velocity of feet per second from a height of feet above the ground. the equation m
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!