1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
julsineya [31]
3 years ago
12

A race car driver must average 200 km/hr for four laps to qualify for a race. because of engine trouble, the car averages only 1

70 km/hr over the first two laps. what average speed must be maintained for the last two laps?
Physics
1 answer:
AnnZ [28]3 years ago
6 0
To know the average, let us assign values for each of the four laps as x, y, v and w. The average of the first two is 170. So, we can determine the sum of x and y:

(x+y)/2 = 170
x = y = 340

Next, we have to find the value for (v+w):
(x+y+v+w)/4 = 200
[340 + (v+w)]/4 = 200
v+w = 460

So, we can now determine the average of the last two laps:
Average = (v+w)/2 = 460/2 = 230 km/h
You might be interested in
A basketball rolls without slipping (starting from rest) down a ramp. If the ramp is sloped by an angle of 4 degrees above the h
slavikrds [6]

Answer:

11.7 m/s

Explanation:

To find its speed, we first find the acceleration of the center of mass of a rolling object is given by

a = gsinθ/(1 + I/MR²) where θ = angle of slope = 4, I = moment of inertia of basketball = 2/3MR²

a = 9.8 m/s²sin4(1 + 2/3MR²/MR²)

  = 9.8 m/s²sin4(1 + 2/3)

  = 9.8 m/s²sin4 × (5/3)

  = 1.14 m/s²

To find its speed v after rolling for 60 m, we use

v² = u² + 2as where u = initial speed = 0 (since it starts from rest), s = 60 m

v = √(u² + 2as) = √(0² + 2 × 1.14 m/s × 60 m) = √136.8 = 11.7 m/s

4 0
3 years ago
A pressure cooker is a pot whose lid can be tightly sealed to prevent gas from entering or escaping. Even without knowing how bi
k0ka [10]

Answer:

a) F₁₂₀ = 1.34 pa A  , b)  F₂₀ = 0.746 pa A

Explanation:

Part. A .    The definition of pressure is

         P = F / A

As the air can approach an ideal gas we can use the ideal gas equation

        P V = n R T

Let's write this equation for two temperatures

       P₁ V = n R T₁

       P₂2 V = n R T₂

       P₁ / P₂ = T₁ / T₂

point 1 has a pressure of P₁ = pa and a temperature of (20 + 273) K, point 2 is at (120 + 273) K, we calculate the pressure P₂

       P₂ = P₁ T₂ / T₁

       P₂ = pa 393/293

       P₂ = 1.34 pa

We calculate the strength

       P₂ = F₁₂₀ / A

       F₁₂₀ = 1.34 pa A

Part B

In this case the data is

Point 1 has a temperature of 393K and an atmospheric pressure (P₁ = pa), point 2 has a temperature of 293K, let's calculate its pressure

        P₁ / P₂ = T₁ / T₂

       P₂ = P₁ T₂ / T₁

       P₂ = pa 293/393

       P₂ = 0.746 pa

Let's calculate the force (F20), from this point

      F₂₀ / A = 0.746 pa

     F₂₀ = 0.746 pa A

6 0
3 years ago
During one cycle, a refrigerator removes 500 J from a cold reservoir and discharges 800 J to its hot reservoir. (a) What is its
Paraphin [41]

Answer:

a)COP = 1.67

b) W = 300 J

Explanation:

given,

refrigerator removes = 500 J from a cold reservoir

discharge = 800 J to its hot reservoir

a) COP = \dfrac{Q}{w}      

   COP = \dfrac{500}{800-500}

   COP = 1.67                        

b) heat per cycle exhausted to the

     W + 500 = 800                        

     W = 800- 500                        

      W = 300 J                                  

5 0
4 years ago
If a current-carrying wire is in a magnetic field, in what direction will a force be exerted on the wire?.
astraxan [27]

Answer:

The magnetic force on a current-carrying wire is perpendicular to both the wire and the magnetic field with direction given by the right hand rule.

4 0
2 years ago
A 75 kg bungee jumper jumps off with zero initial speed from a high cliff with a bungee cord tied to her ankle. At some time dur
stich3 [128]

Answer:

The elastic potential energy PE=143.47kJ

Explanation:

This problem bothers on the potential energy stored in a material.

Given data

Mass of the bungee jumper

m= 75kg

Height of jump down the cliff h=195m

We know that the elastic potential energy stored is same as the potential energy of the bungee jumper

PE= 1/2kx²= mgh

Assuming g is 9.81m/s²

PE= 75*9.81*195

PE= 143471.25J

PE=143.47kJ

What is potential energy?

Potential energy is the energy possessed by a body by virtue of it position.

4 0
3 years ago
Other questions:
  • In gas chromatography, what are the advantages of (a) temperature programming? (check all that apply.)
    15·1 answer
  • X=16.2 cos(4.68t+0.420). What is the velocity of the oscillator at t=7.97 s?
    5·2 answers
  • A crane lift a cargo 10 m off the ground. If the the crane lifts the cargo box twice as high the potential energy will increase
    7·2 answers
  • Two 110 kg bumper cars are moving toward each other in opposite directions. Car A is moving at 8 m/s and Car Z at –10 m/s when t
    14·1 answer
  • Three balls are kicked from the ground level at some angles above horizontal with different initial speeds. All three balls reac
    10·1 answer
  • A 1,700kg car is being used to give a 1,400kg car a push start by exerting a force of 140N the impulse on the smaller car during
    8·1 answer
  • Every exercise regimen should include both a warm-up and a cool down.
    5·1 answer
  • Yagnasree M.,........................ <br> ​
    13·1 answer
  • You roll a toy car, and it moves 10 meters in five seconds. What is the car's velocity?
    7·1 answer
  • what image that is produced when the object is placed between the focal point and the lens. your statement must contain three ch
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!