All categories

2 years ago

The work done by static friction can be : a. Zero

Physics

1 answer:

mario62 [17]2 years ago

5 0

Answer:

A. Zero

Explanation:

The definition of work is related with the energy that a force 'F' implies in a displacement 'Δx'; it means that it is necessary that the body which is over the force comes under a displacement to develop work. The static friction is a force which is only present when there is no movement; when a force overcome the static friction force, the dynamic friction force appears and it is said that the static one disappear. In that sense, the static friction won't ever be a force that can induce a displacement, so the work done by this force will always be zero.

You might be interested in

A 15.0 Ohms resistor is connected in series to a 120V generator and two 10.0 Ohms resistors that are connected in parallel to ea

Nostrana [21]

Hi there! :)

Reference the diagram below for clarification.

We must begin by knowing the following rules for resistors in series and parallel.

In series:
$R_T = R_1 + R_2 + ... + R_n$

In parallel:
$\frac{1}{R_T} = \frac{1}{R_1} + \frac{1}{R_2} + ... + \frac{1}{R_n}$

We can begin solving for the equivalent resistance of the two resistors in parallel using the parallel rules.

$\frac{1}{R_{T, parallel}} = \frac{1}{10} + \frac{1}{10}\\\\\frac{1}{R_{T, parallel}} = \frac{2}{10} = \frac{1}{5}\\\\R_{T, parallel} = 5\Omega$

Now that we have reduced the parallel resistors to a 'single' resistor, we can add their equivalent resistance with the other resistor in parallel (15 Ohm) using series rules:
$R_T = 15 + 5\\\\\boxed{R_T = 20 \Omega}$

We can use Ohm's law to solve for the current in the circuit.

$i = \frac{V}{R_T}\\\\i = \frac{120}{20} = \boxed{6 A}$

For resistors in series, both resistors receive the SAME current.

Therefore, the 15Ω resistor receives 6A, and the parallel COMBO (not each individual resistor, but the 5Ω equivalent when combined) receives 6A.

In this instance, since both of the resistors in parallel are equal, the current is SPLIT EQUALLY between the two. (Current in parallel ADDS UP). Therefore, an even split between 2 resistors of 6 A is <u>3A for each 10Ω resistor</u>.

Since the 15.0 Ω resistor receives 6A, we can use Ohm's Law to solve for voltage.

$V = iR\\\\V = (6)(15) = \boxed{90 V}$

4 0

1 year ago

The intensity of sunlight falling on the earth is about 1.4 kw/m2 (before any gets absorbed by our atmosphere). at what rate doe

xxTIMURxx [149]

The area of the Earth (Ae) that is irradiated by is given by:

Ae = 4πRe^2, where Re = Distance from Sun to Earth
Substituting;
Ae = 4π*(1.5*10^8*1000)^2 = 2.827*10^23 m^2

On the Earth, insolation (We) = Psun/Ae

Therefore,
Psun (Rate at which sun emits energy) = We*Ae = 1.4*2.827*10^23 = 3.958*10^23 kW = 3.958*10^26 W

6 0

2 years ago

The distance between two consecutive nodesof a standing wave is 20.9cm.Thehandgen-erating the pulses moves up and down throughac

irina1246 [14]

Answer:

Velocity, v = 0.239 m/s

Explanation:

Given that,

The distance between two consecutive nodes of a standing wave is 20.9 cm = 0.209 m

The hand generating the pulses moves up and down through a complete cycle 2.57 times every 4.47 s.

For a standing wave, the distance between two consecutive nodes is equal to half of the wavelength.

$\dfrac{\lambda}{2}=0.209\ m\\\\\lambda=0.418\ m$

Frequency is number of cycles per unit time.

$f=\dfrac{2.57}{4.47}\\\\f=0.574\ Hz$

Now we can find the velocity of the wave.

Velocity = frequency × wavelength

v = 0.574 × 0.418

v = 0.239 m/s

So, the velocity of the wave is 0.239 m/s.

4 0

2 years ago

All substances are built from

Greeley [361]

An atom. Hope this helped

6 0

3 years ago

If a block of wood has a density of 0.6g/cm3 and a mass of 120g what is the volume

Luda [366]

Answer:

It would be 39 :))

Explanation:

6 0

3 years ago