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
murzikaleks [220]
3 years ago
11

A person driving her car at 48 km/h approaches an intersection just as the traffic light turns yellow. She knows that the yellow

light lasts only 2.0 s before turning to red, and she is 30 m away from the near side of the intersection (Fig. 2-29). Should she try to stop, or should she make a run for it? The intersection is 15 m wide. Her car's maximum deceleration is -7.0 m/s2, whereas it can accelerate from 48 km/h to 70 km/h in 6.6 s. Ignore the length of her car and her reaction time. If she hits the brakes, how far will she travel before stopping?
Physics
1 answer:
trasher [3.6K]3 years ago
4 0

Answer:

She must stop the car  before interception, distance traveled 12.66 m

Explanation:

We will take all units to the SI system

Vo = 48Km / h (1000m / 1Km) (1h / 3600s) = 13.33 m / s

V2 = 70 Km / h = 19.44 m / s

We calculate the distance traveled before stopping

X = Vo t + ½ to t²

Time is what it takes traffic light to turn red  is t = 2.0 s

X = 13.33 2 + 1.2 (-7) 2²

X = 12.66 m

It stops car before reaching the traffic light turning to red

Let's analyze what happens if you accelerate, let's calculate the acceleration of the vehicle

     V2 = Vo + a t2

      a = (V2-Vo) / t2

      a = (19.44-13.33) /6.6

      a = 0.926 m / s2

This is the acceleration to try to pass the interception, now let's calculate the distance it travels in the time the traffic light changes from yellow to red (t = 2.0 s)

X = Vo t + ½ to t²

X = 13.33 2 + ½ 0.926 2²

X = 28.58 m

Since the vehicle was 30 m away, the interception does not happen

You might be interested in
• The average length is ________ cm. This is the mean or average. b)• Subtract the highest value from the lowest value: ________
coldgirl [10]
16, 5 , 3 = 16+5+3= 24 + 3

So at the end put 24 + 3 cm
And put 16 for the lengths
For the value 5 and for the diving thingy 3
7 0
3 years ago
Which diagram is the best representation of gas molecules in a closed container? A. Diagram A B. Diagram B C. Diagram C D. Diagr
WITCHER [35]
Gas "floats" so if there are examples or pictures it would be the one with the most evenly spread out "dots". 
8 0
2 years ago
In which century was the DNA database established?
krok68 [10]
DNA database was established in 1995
8 0
3 years ago
The distance that a spring will stretch varies directly as the force applied to the spring. A force of 8080 pounds is needed to
xxTIMURxx [149]

Answer:

F₂= 210 pounds

Explanation:

Conceptual analysis

Hooke's law

Hooke's law establishes that the elongation (x) of a spring is directly proportional to the magnitude of force (F) applied to it, provided that said spring is not permanently deformed:

F= K*x   Formula (1)

Where;

F  is the magnitude of the force applied to the spring in Newtons (Pounds)

K is the elastic spring constant, which relates force and elongation. The higher its value, the more work it will cost to stretch the spring. (Pounds/inch)

x the elongation of the spring (inch)

Data

The data given is incorrect because if we apply them the answer would be illogical.

The correct data are as follows:

F₁ =80 pounds

x₁= 8 inches

x₂= 21  inches

Problem development

We replace data in formula 1 to calculate  K :

F₁= K*x₁

K=( F₁) / (x₁)

K=( 80) / (8) = 10 pounds/ inche

We apply The formula 1 to calculate  F₂

F₂= K*x₂

F₂= (10)*(21)

F₂= 210 pounds

8 0
3 years ago
What is the calculation for elastic potential?
grin007 [14]
Elastic potential energy is equal to the force times the distance of movement. Elastic potential energy = force x distance of displacement. Because the force is = spring constant x displacement, then the Elastic potential energy = spring constant x displacement squared.
3 0
3 years ago
Other questions:
  • What do the four terrestrial planets have in common?
    10·1 answer
  • A car starts from rest and speeds up at 2.2m/s^2 after the traffic light turns green , how far will it have gone when it os trav
    8·1 answer
  • Consider the flask apparatus below, which contains 2.00 L of H2 at a pressure of 353 torr and 1.00 L of N2 at an unknown pressur
    15·2 answers
  • When an ice cube in a glass of water melts, the water level _____. A. remains the same B. rises C. falls
    7·2 answers
  • Resistance in wires causes electrical energy to be converted to what form of energy? sound chemical energy nuclear energy therma
    8·1 answer
  • 3. A 0.35 kg puck slides across the ice with an average force of friction of 0.15 N acting on it. It slides 82 m before coming t
    6·1 answer
  • A swimmer is capable of swimming at 1.4m/s in still water. a. How far downstream will he land if he swims directly across a 180m
    6·2 answers
  • You throw a football straight up. Air resistance can be neglected. When the football is 4.00 mm above where it left your hand, i
    14·1 answer
  • Whoever get this right gets free cookies. best deal. ( BASIC PHYSICS QUESTION )
    14·1 answer
  • A small car of mass 1200 kg traveling east at 60m/s collides at an intersection with a truck of mass 3000 kg that is traveling d
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!