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RUDIKE [14]
3 years ago
10

You drive on Interstate 10 from San Antonio to Houston, half the time at 72 km/h and the other half at 98 km/h. On the way back

you travel half the distance at 72 km/h and the other half at 98 km/h. What is your average speed (a) from San Antonio to Houston, (b) from Houston back to San Antonio, and (c) for the entire trip?
Physics
1 answer:
zimovet [89]3 years ago
7 0

Answer: a. 85km/hr b.82.3km/hr

c. 84km/hr

Explanation: first let take the total time from San Antonio to Houston to be 2hr.

Half time 1hr was covered with speed of 72km/hr

Distance = speed*time=72km/hr *1hr

=72km

So too with the second half of 1hr covered with speed of 98km/hr

Distance = 98km

Total distance from Houston to San Antonio is 98+72 =170km

a. Average speed from San Antonio to Houston is

S1 =170/2

=85km/hr

b.half distance from Houston to San Antonio which is 170km/2

= 85km was covered with speed of 72km/hr first half, so time

t = dist/speed

t = 85/72 = 1hr 12 mins

Remaining 85 km covered with a speed of 98km/hr

Time = 85/98 = 0.88*60min

= 52 mins

Total time = 1hr +12mins +52mins

=2hr4mins= 124/60 hr

So average speed = distance/time

=170/124/60

Using reciprocal law

Average speed S2= 170*60/124

= 82.3km/hr

C. Average speed to and fro(entire tripe)

= (85+82.3)/2

=84km/hr

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As an object moves, the distance it travels increases with time. Agree Disagree
egoroff_w [7]

Answer:

Agree

Explanation:

Distance is described as "how much ground an object is covered" in physics, and because the object is moving, no matter which direction, it is constantly gaining more distance. You can think of the object as a car, and as the car is moving down a highway it is gaining more and more distance as the seconds go by.

You might be confused with the term displacement, "how far out of place an object is" which in this case would be false.

Does that make sense?

3 0
3 years ago
Particles q1 = +8.0 UC, 92 = +3.5 uc, and
Olin [163]

Answer:

   F_total = 29.4 N,    directed to the right of particle 2

Explanation:

We must solve this problem in parts, first we calculate each force and then we apply Newton's law to add the forces.

Let's use Coulomb's law to calculate each force

         F = k \frac{q_1q_2}{r_{12}^2}

particles 1 and 2

q₁ = 8.0 10⁻⁶ C, q₂ = 3.5 10⁻⁶ C x₁₂ = 0.10 m

         F₁₂ = 9 10⁹ 8.0 3.5 10⁻¹² / 0.1²

         F₁₂ = 2.59 10¹ N

Since the two charges are of the same sign, this force is repulsive and is directed towards the positive side of the x axis.

particles 2 and 3

q₂ = 3.6 10⁻⁶ C, q₃ = 2.5 10⁻⁶ C, x₂₃ = 0.15 m

we calculate

        F₂₃ = 9 10⁹ 3.5 2.5 10⁻¹²/ 0.15²

        F₂₃ = 3.5 N

as the charge is of different sign, the force is attractive, therefore it is directed to the right of the load 2

Now we add the forces as vectors

        F_total = ∑ F = F₁₂ + F₂₃

        F_total = 25.2 +3.5

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directed to the right of particle 2

5 0
3 years ago
Read 2 more answers
You place a 500 g block of an unknown substance in an insulated container filled 2 kg of water. The block has an initial tempera
Nina [5.8K]

Answer:

3349J/kgC

Explanation:

Questions like these are properly handled having this fact in mind;

  • Heat loss = Heat gained

Quantity of heat = mcΔ∅

m = mass of subatance

c = specific heat capacity

Δ∅ = change in temperature

m₁c₁(∅₂-∅₁) = m₂c₂(∅₁-∅₃)

m₁ = mass of block = 500g = 0.5kg

c₁  = specific heat capacity of unknown substance

∅₂ = block initial temperature = 50oC

∅₁ = equilibrium temperature of block and water after mix= 25oC

m₂= mass of water = 2kg

c₂ = specific heat capacity of water = 4186J/kg C

∅₃ = intial temperature of water = 20oC

0.5c₁(50-25) = 2 x 4186(25-20)

And we can find c₁ which is the unknown specific heat capacity

c₁ = \frac{2*4186*5}{0.5*25}= 3348.8J/kg C≅ 3349J/kg C

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go with D. cyanobactweia,sea scorpion,birds,saber-toothed cats
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Zina [86]
That would be the dump truck. Momentum depends on how heavy a certain object is in motion. The more weight it has the harder it is to stop.
4 0
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