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AleksAgata [21]

2 years ago

11

A race car driver must average 200km/hr for four laps to qualify for a race. Because of engine trouble, the car averages only 17

0km/hr over the first two laps. What is the average speed must be maintained for the last two laps

1 answer:

vampirchik [111]2 years ago

5 0

The average speed would have to be 260 km/hr due to the driver originally going 30 km/hr too slow the first two laps

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What is the value of the composite constant (gmer2e), to be multiplied by the mass of the object mo in the equation above? expre

Bezzdna [24]

The solution would be like this for this specific problem:

F = (G Me Mo) / Re^2

F / Mo = (G Me) / Re^2

G = gravitational constant = 6.67384 * 10^-11 m3 kg-1 s-2

Me = 5.972 * 10^24 kg

Re^2 = (6.38 * 10^6)^2 m^2 = 40.7044 * 10^12 m^2 = 4.07044 * 10^13 m^2

G Me / Re^2 = (6.67384 * 10-11 * 5.972 * 10^24) / 4.0704 * 10^13 = 9.7196 m/s^2

9.7196 m/s^2 = acceleration due to Earth’s gravity

Therefore, the value of the composite constant (Gme / r^2e) that is to be multiplied by the mass of the object mo in the equation above is 9.7196 m/s^2.

8 0

1 year ago

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You are standing at the midpoint between two speakers, a distance D away from each. The speakers are playing the exact same soun

Rzqust [24]

Answer:

Explanation:

wave length of sound waves = velocity / frequency

= 340 / 170

λ = 2 m.

When the position of man is exactly at the meddle point between the speakers , sound waves from the speakers reaching man are in same phases ( path difference is zero. ) so intensity of sound is maximum .

Now , the man starts moving towards one of the speakers , his distance from one speaker becomes closer than the other creating path difference for the sound waves reaching his ears.

If he walks a distance of .5 m towards one speaker , path difference created

= .5 x 2 = 1 m

So , path difference = λ /2 ,

there will be destructive interference so minimum sound will be heard there.

When he walks a distance of 1 m , path difference created = 2m

path difference = λ

so there is constructive interference and maximum sound will be heard there.

Again we he walks a distance of 1.5 m , path difference created = 3 m

path difference = 3 λ /2

So there will be destructive interference so minimum sound will be heard there.

In this way we see that man starts from a point of maximum sound intensity , reaches a point of minimum sound intensity , then reaches a point of maximum sound intensity . At last he reaches a position of minimum sound intensity.

3 0

2 years ago

A steel rod with a length of l = 1.55 m and a cross section of A = 4.45 cm2 is held fixed at the end points of the rod. What is

Blababa [14]

To solve this problem it is necessary to apply the concepts related to thermal stress. Said stress is defined as the amount of deformation caused by the change in temperature, based on the parameters of the coefficient of thermal expansion of the material, Young's module and the Area or area of the area.

$F = AY\alpha \Delta T$

Where

A = Cross-sectional Area

Y = Young's modulus

$\alpha$ = Coefficient of linear expansion for steel

$\Delta T$ = Temperature Raise

Our values are given as,

$A = 4.45cm^2$

$T = 37K$

$\alpha = 1.17*10^{-5}K^{-1}$

$Y = 200*10^9Gpa$

Replacing we have,

$F = (4.45*10^{-4})(200*10^9)(1.17*10^{-5})(37)$

$F = 38526.1N$

Therefore the size of the force developing inside the steel rod when its temperature is raised by 37K is 38526.1N

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2 years ago

The value of specific heat for copper is 390 J/kg⋅C∘, for aluminun is 900 J/kg⋅C∘, and for water is 4186 J/kg⋅C∘.

abruzzese [7]

Answer:

The equilibrium temperature is

21.97°c

Explanation:

This problem bothers on the heat capacity of materials

Given data

specific heat capacities

copper is Cc =390 J/kg⋅C∘,

aluminun Ca = 900 J/kg⋅C∘,

water Cw = 4186 J/kg⋅C∘.

Mass of substances

Copper Mc = 235g

Aluminum Ma = 135g

Water Mw = 825g

Temperatures

Copper θc = 255°c

Water and aluminum calorimeter θ1= 16°c

Equilibrium temperature θf =?

Applying the principle of conservation of heat energy, heat loss by copper equal heat gained by aluminum calorimeter and water

McCc(θc-θf) =(MaCa+MwCw)(θf-θ1)

Substituting our data into the expression we have

235*390(255-θf)=

(135*900+825*4186)(θf-16)

91650(255-θf)=(3574950)(θf-16)

23.37*10^6-91650*θf=3.57*10^6θf- +57.2*10^6

Collecting like terms and rearranging

23.37*10^6+57.2*10^6=3.57*10^6θf+91650θf

8.2*10^6=3.66*10^6θf

θf=80.5*10^6/3.6*10^6

θf =21.97°c

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1 year ago

John runs 1.0 m/s at first, and then accelerates to 1.6 m/s during

erastova [34]

Answer: $0.13m/s^2$

Explanation:

$Formula: a=\frac{V_2-V_1}{t}$

Where;

a = acceleration

V2 = final velocity

V1 = initial velocity

t = time

If John runs 1.0 m/s first, we assume this is V1. He accelerates to 1.6 m/s; this is V2.

$a=\frac{1.6m/s-1.0m/s}{4.5s}$

$a=\frac{0.6m/s}{4.5s}$

$a=0.13m/s^2$

7 0

2 years ago

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