Ask question

Ask question

All categories

3 years ago

8

John is traveling north at 20 meters/second and his friend Betty is traveling south at 20 meters/second. If north is the positiv

e direction, what are John and Betty's speeds?

2 answers:

Tems11 [23]3 years ago

6 0

Explanation:

John is traveling north at 20 meters/second and his friend Betty is traveling south at 20 meters/second.

We know that the total distance covered divided by total time taken is called speed of an object. It is a scalar quantity i.e. it have only magnitude. While velocity is a vector quantity.

In this case, north direction is considered as positive while south direction is considered as negative.

So, John's speed is 20 meters/second and Betty's speed is 20 meters/second as speed is a scalar quantity.

DanielleElmas [232]3 years ago

3 0

John's velocity is 20 m/s north.
Betty's velocity is 20 m/s south.
Their speeds are both 20 m/s.

You might be interested in

A mole of a monatomic ideal gas at point 1 (101 kPa, 5 L) is expanded adiabatically until the volume is doubled at point 2. Then

Paha777 [63]

Answer:

(a). Check attachment.

(b). 280.305 J.

(c). 31.81 kpa; 38.26K.

(d). 24.05K.

(e). 24.05k; 40kpa.

(f). -138.6J.

Explanation:

(a). Kindly check the attached picture for the diagram showing the four process.

1 - 2 = adiabatic expansion process.

2 - 3 = Isochoric process.

3 - 4 = isothermal process.

4 - 1 = isochoric process.

(b). Recall that the process from 1 to is an adiabatic expansion process.

NB: b = 5/3 for a monoatomic gas.

Then, the workdone = (1/ 1 - 1.66) [ (p1 × v1^b)/ v2^b × v2 - (p1 × v1)].

= ( 1/ 1 - 5/3) [ (101 × 5^5/3) × 10^1 -5/3] - 101 × 5.

Thus, the workdone = 280.305 J.

(c). P2 = P1 × V1^b/ V2^b = 101 × 5^5/3/ 10^5/3 = 31.81 kpa.

T2 = P2 × V2/ R × 1 = 31.81 × 10/ 8.324 = 38.36k.

(d). The process 2 - 3 is an Isochoric process, then;

T3 = T2/P2 × P3 = 38.26/ 31.82 × 20 = 24.05K.

(e). The process 3 - 4 Is an isothermal process. Then, the temperature at 4 will be the same temperature at 3. Tus, we have the temperature; point 3 = point 4 = 24.05k.

The pressure can be determine as below;

P4 = P3 × V3/ V4 = 20 × 10/ 5 = 200/ 5 = 40 kpa.

(f) workdone = xRT ln( v4/v3) = 1 × 8.314 × 24.05 × ln (5/10) = - 138.6 J

6 0

3 years ago

If you connected 10 of these 12V (10 W) lamps in parallel, to the 12V source, how much current would the source have to supply

Flauer [41]

Answer:

$T=8.33A$

Explanation:

From the question we are told that:

Number of battery $n=10$

Voltage source $E=12V$

Lamp Power $P=10W$

Generally the equation for Resistance is mathematically given by

$R=\frac{V^2}{P}$

$R=\frac{12^2}{10}$

$R=14.4ohms$

Therefore

$R_{eq}=\frac{14.4}{10}$

$R_{eq}=1.44$

Generally the equation for Current is mathematically given by

$T=\ffrac{V}{Req}$

$T=\frac{12}{1.44}$

$T=8.33A$

6 0

3 years ago

reviews the approach taken in problems such as this one. A bird watcher meanders through the woods, walking 0.916 km due east, 0

Verizon [17]

Answer:

Displacement: 2.230 km Average velocity: 1.274 $\frac{km}{h}$

Explanation:

Let's represent displacement by the letter S and the displacement in direction 49.7° as A. Displaement is a vector, so we need to decompose all the bird's displacement into their X-Y compoments. Let's go one by one:

0.916 km due east is an horizontal direction and cane be seen as direction towards the negative side of X-axis.

0.928 km due south is a vertical direction and can be seen as a direction towards the negative side of Y-axis.
3.52 km in a direction of 49.7° has components on X and Y axes. It is necessary to break it down using trigonometry,

First of all. We need to sum all the X components and all the Y componets.

∑ $Sx = Ax -0.916$ ⇒ ∑ $Sx = [tex]3.52cos(49.7) - 0.916$

∑ $Sx = 1.361 km$

∑ $Sy = Ay - 0.918$ ⇒ ∑ $Sy = 3.52sin(49.7) - 0.918$

∑ $Sy = 1.767$

The total displacement is calculated using Pythagoeran therorem:

$S_{total} =\sqrt{Sx^{2}+ Sy^{2} }$ ⇒

$S_{total} = 2.230 km$

With displacement calculated, we can find the average speed as follows:

$V = S/t$ ⇒ $V = \frac{2.230}{1.750}$

$V = 1.274\frac{km}{h}$

7 0

3 years ago

Which form of energy is equal to the sum of an object’s kinetic and potential energy?

Natali5045456 [20]

Answer:

Mechanical Energy

Explanation:

The sum of kinetic energy and potential energy of an object is its total mechanical energy.

4 0

3 years ago

The wavelength of a light wave will affect the light’s

Tom [10]

Frequency and color.

6 0

3 years ago