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3 years ago

A drag racer starts from rest and accelerates at 7.4 m/s2. How far will he travel in 2.0 seconds?

Physics

1 answer:

Tamiku [17]3 years ago

8 0

Try this solution:

1. rule for this type of movement:

$S=v_0t+\frac{at^2}{2}, \ where \ a-acceleration,S-distance,v-startSpeed,t-time.$

2. according to the rule described above:

$S=0+\frac{7.4*2^2}{2}=7.4*2=14.8(m)$

answer: 14.8 meters.

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100 POINTS. PLEASE EXPLAIN

Elina [12.6K]

Answer:

(a) 106 kPa

(b) 0.0377 mol

Explanation:

(a) There are three forces on the piston. Atmospheric pressure pushing down, weight pulling down, and pressure of the gas pushing up.

∑F = ma

PA − mg − PₐA = 0

P = (PₐA + mg) / A

P = Pₐ + (mg / A)

P = 101,300 Pa + (40.0 N) / (π (0.05 m²))

P = 106,393 Pa

P = 106 kPa

(b) Use ideal gas law.

PV = nRT

(106,393 Pa) (π (0.05 m²) (0.11 m)) = n (8.314 Pa m³/mol/K) (20 + 273.15) K

n = 0.0377 mol

PV = nRT

(106,393 Pa) (π (0.05 m²) h) = (0.0377 mol) (8.314 Pa m³/mol/K) (200 + 273.15) K

h = 0.178 m

h = 17.8 cm

6 0

4 years ago

Read 2 more answers

A cell has an emf of 1.5 V and an internal resistance of 0.65 Q.

marin [14]

Answer:

Explanation:

1) emf stands for elactro-motive force and represents the ability to move electrical charge carriers. Commonly referred to as Volts.

2) P = VI = 1.5(0.31) = 0.465 ≈ 0.47 W

3) P = 0.465 - I²R = 0.465 - 0.31²(0.65) = 0.402535 W = J/s ≈ 0.40 J

4) 14000 J / 0.40 J/s = 35 000 s or about 9.75 hrs

5 0

3 years ago

Read 2 more answers

An unpolarized light shines on an object that is placed below a crystal. When an observer looks at the object through the crysta

slavikrds [6]

Answer:

See explanation

Explanation:

Solution:-

- light reflected through calcite crystals difference occurs due to the polarity of the light passing through the crystal. Daylight is composed of light vibrating in all planes, whereas reflected light is often restricted to a single plane that is parallel to the surface from which the light is reflected.

- Light that is reflected from the flat surface of a dielectric (or insulating) material is often partially polarized, with the electric vectors of the reflected light vibrating in a plane that is parallel to the surface of the material.

- light waves that have the electric field vectors parallel to the surface are reflected to a greater degree than those with different orientations.

8 0

4 years ago

As part of an interview for a summer job with the Coast Guard, you are asked to help determine the search area for two sunken sh

MrMuchimi

Answer: $37^{\circ}$ North of west

Explanation:

Given

40,000-ton luxury line traveling 20 knots towards west and

60,000 ton freighter traveling towards North with 10 knots

suppose v is the common velocity after collision

conserving momentum in west direction

$20\times 40,000=(20,000+60,000)v\cos \theta$

suppose the final velocity makes \theta angle with x axis

$v\cos \theta =10----1$

Conserving Momentum in North direction

$10\times 60,000=80,000\times v\sin\theta$

$v\sin \theta =\frac{15}{2}----2$

divide 1 and 2

$\tan \theta =\frac{3}{4}$

$\theta =37^{\circ}$

so search in the area $37^{\circ}$ North of west to find the ship

3 0

3 years ago

A pulse of light takes 3.00 ns to travel through air from an emitter to a detector. When a piece of transparent material with a

cupoosta [38]

Answer:

(a) $1.75\times10^8\text{ m/s}$

(b) 1.71

Explanation:

(a) The difference in the times of travel in the two case = $3.20 - 3.00 = 0.20\text{ ns} = 2.0\times10^{-9}\text{ s}$

This difference is the time in the transparent material. With a thickness of 35.0 cm, the speed in the material is

$v = \dfrac{35 cm}{2.0\times10^{-9}\text{ s}}=\dfrac{0.35 m}{2.0\times10^{-9}\text{ s}} = 1.75\times10^8\text{ m/s}$

(b) The refractive index of the material is the ratio of the velocity of light in vacuum to its velocity in the material. Using speed of light in vacuum as $c = 3.00\times10^8\text{ m/s}$ , the refractive index, $n$ , is

$n=\dfrac{c}{v} = \dfrac{ 3.00\times10^8\text{ m/s}}{1.75\times10^8\text{ m/s}}= 1.71$

4 0

3 years ago