All categories

2 years ago

An object on a number line moved from x = 15 cm to x = 165 cm and then

Physics

2 answers:

mel-nik [20]2 years ago

5 0

Answer:

The average velocity of the object is 0.1cm/s

Explanation:

Given that the object travels from point 15cm to 165cm and back to 25cm within 100 seconds

The average velocity is calculated as thus.

Average Velocity = ∆D/t

Where ∆D represent the displacement.

The displacement is calculated as follows.

∆D = End point - Start Point.

From the question, the end and start point are 25cm and 15cm respectively.

Hence,

∆D = 25cm - 15cm

∆D = 10cm.

t = 100 seconds

So, Average Velocity = 10cm/100s

Average Velocity = 0.1cm/s

Hence, the average velocity of the object is 0.1cm/s

olasank [31]2 years ago

3 0

Answer:

v_avg = 2.9 cm/s

Explanation:

The average velocity of the object is the sum of the distance of all its trajectories divided the time:

$v_{avg}=\frac{x_{all}}{t}$

x_all is the total distance traveled by the object. In this case you have that the object traveled in the first trajectory 165cm-15cm = 150cm, and in the second one, 165cm - 25cm = 140cm

Then, x_all = 150cm + 140cm = 290cm

The average velocity is, for t = 100s

$v_{avg}=\frac{290cm}{100s}=2.9\frac{cm}{s}$

hence, the average velocity of the object in the total trajectory traveled is 2.9 cm/s

You might be interested in

A bucket of water experiencing a gravitational force of 525 N is pulled up from a water well. The net force in the y-direction i

lukranit [14]

Answer:

6n!!!!!!!!!!!!!!!!!!

Explanation:

nnnn

8 0

2 years ago

A windowpane is half a centimeter thick and has an area of 1.0 m2. The temperature difference between the inside and outside sur

polet [3.4K]

To solve this problem it is necessary to apply the concepts related to the heat flux rate expressed in energetic terms. The rate of heat flow is the amount of heat that is transferred per unit of time in some material. Mathematically it can be expressed as:

$\frac{Q}{t} = \frac{kA}{L} (T_H - T_C)$

Where

k = 0.84 J/s⋅m⋅°C (The thermal conductivity of the material)

$A = 1m^2$ Area

$L = 5*10^{-3}m$ Length

$T_H$ = Temperature of the "hot"reservoir

$T_C$ = Temperature of the "cold"reservoir

Replacing with our values we have that,

$\frac{Q}{t} = \frac{kA}{L} (T_H - T_C)$

$\frac{Q}{t} = \frac{(0.84)(1)}{0.005} (15)$

$\frac{Q}{t} = 2520J/s$

Therefore the correct answer is B.

3 0

2 years ago

Which phrases describe NASA's goals in the coming years? Check all that apply.

Serggg [28]

Answer:

1, 3 and 4

Explanation:

Did the test and saw the answers.

3 0

2 years ago

Read 2 more answers

Deep-sea divers often breathe a mixture of helium and oxygen to avoid getting the "bends" from breathing high-pressure nitrogen.

kvv77 [185]

Answer:

0.69444 m, 0.08152 m, 0.32407 m, 0.03804 m

Explanation:

v = Velocity of sound

f = Frequency

Length of vocal tract is given by

$L=\dfrac{v}{4f}$

At f = 270 Hz v = 750 m/s

$L=\dfrac{750}{4\times 270}\\\Rightarrow L=0.69444\ m$

At f = 2300 Hz v = 750 m/s

$L=\dfrac{750}{4\times 2300}\\\Rightarrow L=0.08152\ m$

At f = 270 Hz v = 350 m/s

$L=\dfrac{350}{4\times 270}\\\Rightarrow L=0.32407\ m$

At f = 2300 Hz v = 350 m/s

$L=\dfrac{350}{4\times 2300}\\\Rightarrow L=0.03804\ m$

3 0

2 years ago

When a gas is rapidly compressed (say, by pushing down a piston) its temperature increases. When a gas expands against a piston,

shusha [124]

Answer:

Explained in explanation

Explanation:

The first law of thermodynamics states that the change in internal energy of a system(ΔU) is equal to the sum of the net heat transfer into the system(Q) and the net work done on the system(W). In equation, this law is;

ΔU = Q + W

Now, when there's gas inside a container with a movable piston that's tightly fitting, we will assume that the piston can move up and down thereby compressing the gas or allowing the gas to expand against it.

Now these gas molecules inside the container possess kinetic energy. Thus, the internal energy(U) of the system is simply the sum of all the kinetic energies of the individual gas molecules present in the container.

Therefore, if the temperature(T) of the gas increases, then the speed and internal energy(U) of the gas molecules will also increase. In the same way, if the temperature of the gas decreases, the speed and internal energy of the gas molecules would also decrease.

Now, back to the question, when the piston is pushed down, it does work on the gas and the gas does negative work on the piston. Thus, the gas will be get compressed to a smaller space, and thereby making the gas molecules to hit the piston at a faster rate. Thus, there is a decrease in speed and as we saw earlier that when there is a decrease in speed, it means temperature has decreased.

Whereas, when the piston is moved up, the gas does positive work on the piston and the speed of the gas molecules will increase. Like I said earlier that increase in speed means increase in temperature.

4 0

2 years ago