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3 years ago

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Physics

1 answer:

Marysya12 [62]3 years ago

4 0

D only kinetic energt because if it had heluim or any thing jt will float up

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41. City A lies 30 km directly south of city B. A bus, beginning at city A travels 50 km at 37° north of east to reach city C. H

Nana76 [90]

Answer:

B) 40 km West

Explanation:

Let position of B is origin so with respect of City B the position of A is given as

$r_A = 30 km$ south of city B

now Bus starts from City A and travels a distance of 50 km at 37 degree North of East to reach city C

so it is

$r_{CA} = 50(cos37\hat i + sin37 \hat j)$

$r_{CA} = 40\hat i + 30\hat j$

now the position of C is given with respect to A

in order to find the position of C with respect to B we can say

$r_C = r_{CA} + r_A$

$r_C = 40\hat i + 30\hat j + (-30 \hat j)$

$r_C = 40 \hat i$

so in order to reach at city B from city C bus has to travel 40 km towards West

7 0

3 years ago

Design a battery to be constructed of D-cells, rated at 3Amp-hours and voltage 1.5V, that will provide a maximum operating curre

Free_Kalibri [48]

Answer:

9 hours

Explanation:

For each battery:

Current = 1 A

Voltage = 1.5 V

current and EMF required = 5.0 A and 4.5 V

Since each battery has a current of 1 A, we'll need to link five of them in parallel with our load to get a current of 5 A. so that the total current equals 5 amps . Now that each battery has a 1.5 V voltage drop and we require an emf of 4.5 V, we would use three batteries in series rather than a single battery. So, there is a need to must substitute every single battery with three batteries in series for all five single batteries linked in parallel.

So, the total no. of batteries is

= 5 × 3 = 15 batteries.

On each battery, the charge is = 3 amp hours

∴

The total charge = 15 × 3 = 45 amp hours.

Since the charge transferred within 1 hour = 5 amp

Then, the required lifetime of the battery is:

= 45 amp-hours/ 5 amp

= 9 hours

6 0

3 years ago

El tren Lima la Orolla va a una velocidad de 10 km/h y de pronto aplica el freno por un derrumbe en la via. Si demora 18 segundo

Naya [18.7K]

Answer:

Distancia = 50.04 metros

Explanation:

Dados los siguientes datos;

Velocidad = 10 km/h

Tiempo = 18 segundos

Para encontrar la distancia;

Conversión:

10 km/h = 10 * 1000/3600 = 2.78 m/s

Distancia = velocidad * tiempo

Distancia = 2.78 * 18

Distancia = 50.04 metros

Por lo tanto, el tren viajaría 50.04 metros antes de detenerse por completo.

7 0

3 years ago

Locomotion is the act of staying stationary. True False 20 POINTS

Fittoniya [83]

Answer:

False

Explanation:

Locomotion is associated with movement.

The word is derieved from two Latin words,

Loco----place

Motio----to move.

8 0

3 years ago

A low orbit satellite at 100 km altitude had a camera that resolved a car location to within 0.3 meter. Find the minimum diamete

NeX [460]

Answer:

Minimum diameter of the camera lens is 22.4 cm

The focal length of the camera's lens is 300cm

Explanation:

y = Resolve distance = 0.3 m

h = Height of satellite = 100 km

λ = Wavelength = 550 nm

Angular resolution

$tan\theta\approx \theta =\frac{y}{h}\\\Rightarrow \theta=\frac{0.3}{100\times 10^3}=3\times 10^{-6}$

From Rayleigh criteria

$sin\theta=1.22\frac{\lambda}{D}\\\Rightarrow D=1.22\frac{\lambda}{sin\theta}\\\Rightarrow D=1.22\frac{550\times 10^{-9}}{sin3\times 10^{-6}}=0.2236\ m=22.4\ cm$

Minimum diameter of the camera lens is 22.4 cm

Relation between resolvable feature, focal length and angular resolution

$d=f\Delta \theta\\\Rightarrow f=\frac{d}{\Delta \theta}\\\Rightarrow f=\frac{9\times 10^{-6}}{3\times 10^{-6}}=3\ m=300\ cm$

The focal length of the camera's lens is 300cm

3 0

3 years ago