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
prisoha [69]
3 years ago
7

You are driving down the road at 30 mph (miles per hour) when you see the traffic light change to red. The red light is 300 feet

from you. How much time will it take you to stop? (please provide explanation)
Physics
1 answer:
RSB [31]3 years ago
8 0

Answer:

45 s

Explanation:

To find the time it takes to stop, we first find the deceleration, a of the car from

v² = u² + 2as and a = (v² - u²)/2s were v = final velocity of car = 0 mph = 0 m/s, u = initial velocity of car = 30 mph = 30 × 1609.34 ft ÷ 3600 s = 13.41 ft/s and s = distance = 300 ft. Substituting the values into a, we ave

a = (v² - u²)/2s = (0² - 13.41²)/2×300 = -0.3 ft/s²

We then find the time for this deceleration from v = u + at ⇒ t = (v - u)/a

t = (v - u)/a = (0 - 13.41 ft/s)/-0.3 ft/s² = - 13.41 ft/s/-0.3 ft/s² = 44.7 s ≅ 45 s

So it takes 45 seconds to stop.

You might be interested in
How is a coil of current carrying wire similar to a bar magnet
zalisa [80]

Answer:

 When an electric current flows, the shape of the magnetic field is very similar to the field of a bar magnet

Explanation:

5 0
3 years ago
Determine the amount of work done by the applied force when a 87 N force is applied to move a 15 kg object a horizontal
elena-s [515]

Answer:

391.5 J

Explanation:

The amount of work done can be calculated using the formula:

  • W = F║d
  • where the force is parallel to the displacement

Looking at the formula, we can see that the mass of the object does not affect the work done on it.

Substitute the force applied and the displacement of the object into the equation.

  • W = (87 N)(4.5 m)
  • W = 391.5 J  

The amount of work done on the object is 391.5 J in order to move it 4.5 meters with an applied force of 87 Newtons.

5 0
2 years ago
Read 2 more answers
How to find the maximum amount of a substance that will dissolve using a graph?
soldi70 [24.7K]
Solubility indicates the maximum amount of a substance that can be dissolved in a solvent at a given temperature. Such a solution is called saturated. Divide the mass of the compound by the mass of the solvent and then multiply by 100 g to calculate the solubility in g/100g .
8 0
3 years ago
Which phrase describes speed?
Anna11 [10]

Answer:

the answer is B

Explanation:

speed is the rate at which the distance covered changes or the distance divided by the time taken.

scalar is always positive.

6 0
2 years ago
Read 2 more answers
Which section of the graph represents negative acceleration?
agasfer [191]
The area between the 10 and the 12.
8 0
3 years ago
Read 2 more answers
Other questions:
  • Calculate the linear acceleration (in m/s2) of a car, the 0.330 m radius tires of which have an angular acceleration of 13.0 rad
    14·1 answer
  • What are non examples of a medium?
    15·1 answer
  • Calculate the acceleration if you push with a 20-N horizontal force against a 2-kg block on a horizontal friction- free air tabl
    5·1 answer
  • My Notes A flat loop of wire consisting of a single turn of cross-sectional area 7.80 cm2 is perpendicular to a magnetic field t
    10·1 answer
  • What happens to some of the sun's energy that does not reach the earth's surface?
    9·1 answer
  • F all of the energy in a falling object's gravitational potential energy store is transferred to its kinetic energy store by the
    7·1 answer
  • Use relative dating in a sentence.
    12·1 answer
  • How is an image from a CT scan made from 2D X-ray images?
    5·2 answers
  • Students perform a set of experiments by placing a block of mass m against a spring, compressing the spring a distance x along a
    9·1 answer
  • sports photographers often use large aperture, long focal length lenses. what limitations do these lenses impose on the photogra
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!