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
givi [52]
3 years ago
7

A motorist is traveling at 20 m/s. He is 60 m from a stoplight when he sees it turn yellow. Is reaction time, before stepping on

the brake, is 0.50 s. What steady acceleration (slowing down) while braking will bring him to a stop right at the light?
Physics
1 answer:
Gnesinka [82]3 years ago
5 0
V₀ = V₁ + 2ax
V₀ = final velocity which is 0 m/s
V₁ = initial velocity which is 20 m/s
x = distance which is 60-(0.5 x 20) =50m
     this is because his reaction time is 0.5 sec so he traveled 10m before stepping on the break paddle.

a= (V₀-V₁) / 2x
  = (0-20) / 2*50
  = -0.2m/s
the negative is because it is a deceleration speed hence it is 0.2m/s
You might be interested in
A syringe of volume 16 cm3 is filled with air to a pressure of 1.03 atm. If the piston of the syringe is pushed to change the vo
denpristay [2]
<h3>Answer:</h3>

189.07 kPa

<h3>Explanation:</h3>

Concept tested: Boyle's law

<u>We are given;</u>

  • Initial volume of the syringe, V1 is 16 cm³
  • Initial pressure of the syringe, P1 is 1.03 atm
  • New volume of the syringe, V2 is 8.83 cm³

We are required to calculate the new pressure of the syringe;

  • We are going to use the concept on Boyle's law of gases.
  • According to the Boyle's law, for a fixed mass of a gas, the pressure is inversely proportional to its volume at constant temperature.
  • That is; P α 1/V
  • At varying pressure and volume, k(constant)  = PV and P1V1=P2V2

Therefore, to get the new pressure, P2, we rearrange the formula;

P2 = P1V1 ÷ V2

     = ( 16 cm³ × 1.03 atm) ÷ 8.83 cm³

    = 1.866 atm.

  • Thus, the new pressure is 1.866 atm
  • But, we need to convert pressure to Kpa
  • Conversion factor is 101.325 kPa/atm

Thus;

Pressure = 1.866 atm × 101.325 kPa/atm

               = 189.07 kPa

Hence, the new pressure of the air in the syringe is 189.07 kPa

3 0
3 years ago
As the ball rolls down the ramp, there are changes in kinetic and potential energy. How much kinetic energy does the ball have w
Trava [24]

Answer: C. 50j

Explanation:

5 0
3 years ago
Read 2 more answers
A cylinder contains a gas at a temperature of 400K. Explain two ways that you can add energy to the gas and raise its temperatur
Lelechka [254]
Heat

You can usually warm something by adding energy. The added energy can be from light, electricity, friction, a chemical reaction, nuclear reaction, or any other kind of energy. When first added to a substance, energy might be concentrated in one atom, but this one will soon bump into others and spread the energy. Eventually, every atom or molecule in the substance will move a bit faster. When the added energy is spread throughout a substance, it is then called heat energy, thermal energy, or, simply heat. All three terms mean the same thing. Heat is a form of energy, so it has the units of energy. In the SI system, this is Joules. Many other units to measure thermal energy are in common use. Calories and BTU's are common heat units.

Temperature

You cannot measure heat directly, but you can detect its effect on a substance. Changes in heat can usually be detected as changes in temperature. Usually, when you add energy to a bunch of atoms they move faster and get hotter. Similarly, if you remove energy from a bunch of atoms, they usually move less and get cooler.
5 0
3 years ago
Why does the comet have tails
docker41 [41]

Answer:

Comets leave long beautiful tails when they come close to the sun. ... But when it approaches the sun, the heat evaporates the comet's gases, causing it to emit dust and microparticles (electrons and ions). These materials form a tail whose flow is affected by the sun's radiation pressure.

Explanation: I just searched it up on the internet lol.

8 0
3 years ago
Read 2 more answers
During a safety test, a car hits a wall and stops in 0.55 s. The net force on the car is 6500 N during the collision. What is th
Kobotan [32]

Answer:

ΔP = 3600 kg m/s.

Explanation:

Change in momentum (ΔP) of the car is the amount of impulse on it. Impulse (I) can be define as the product of force and the time at which it acts.

i.e I = ΔP

But, I = Ft

Ft = ΔP

ΔP = 6500 x 0.55

     = 3575 Ns

     = 3600 kg m/s^{2} x s

ΔP = 3600 kg m/s

The magnitude of the change in momentum of the car is 3600 kgm/s.

6 0
3 years ago
Other questions:
  • A material you are testing conducts electricity but canot be pulled into wires
    10·1 answer
  • Which type of transformer is found outside a residential house
    5·1 answer
  • Which of the following is part of a atom
    9·2 answers
  • A 12 kg bowling ball would require what force to accelerate down and alleyway at a rate of 3 m/s²?
    7·1 answer
  • A 12.0-g plastic ball is dropped from a height of 2.50 m. Just as it strikes the floor, it is moving at a speed of 3.20 m/s. How
    7·1 answer
  • An object weighs 32 newtons. What is its mass if a gravitometer indicates that g = 8.25 m/s?
    15·1 answer
  • Which. describe newtons law of univesel gravitation
    13·1 answer
  • The loudness of a sound is the wave's _______
    14·2 answers
  • A factory has 1200 workers of which 720 are male and the rast are female what percent of workers are female​
    12·1 answer
  • If 12 coulombs of electric charge pass a point in 4.0
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!