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
hammer [34]
3 years ago
7

Now in "real life," this automobile is cruising at 20.5 m/s (equal to 73.8 km/hr) when it is about to hit a pedestrian stuck in

the middle of the road. The super hero Mr. Incredible comes to the rescue. He does not want to get sued, however. Therefore, he will not push the car with a force greater than 2.0 ✕ 104 N; otherwise, the bumper will get damaged. How much time (in s) does he need to stop this car?
Physics
1 answer:
algol133 years ago
5 0

Answer:

He needs 1.53 seconds to stop the car.

Explanation:

Let the mass of the car is 1500 kg

Speed of the car, v = 20.5 m/s

He will not push the car with a force greater than, F=2\times 10^4\ N

The impulse delivered to the object is given by the change in momentum as :

F\times t=mv\\\\t=\dfrac{mv}{F}\\\\t=\dfrac{1500\times 20.5}{2\times 10^4}\\\\t=1.53\ s

So, he needs 1.53 seconds to stop the car. Hence, this is the required solution.

You might be interested in
What ocean depth would the volume of an aluminium sphere be reduced by 0.10%
yKpoI14uk [10]

Answer:

6400 m

Explanation:

You need to use the bulk modulus, K:

K = ρ dP/dρ

where ρ is density and P is pressure

Since ρ is changing by very little, we can say:

K ≈ ρ ΔP/Δρ

Therefore, solving for ΔP:

ΔP = K Δρ / ρ

We can calculate K from Young's modulus (E) and Poisson's ratio (ν):

K = E / (3 (1 - 2ν))

Substituting:

ΔP = E / (3 (1 - 2ν)) (Δρ / ρ)

Before compression:

ρ = m / V

After compression:

ρ+Δρ = m / (V - 0.001 V)

ρ+Δρ = m / (0.999 V)

ρ+Δρ = ρ / 0.999

1 + (Δρ/ρ) = 1 / 0.999

Δρ/ρ = (1 / 0.999) - 1

Δρ/ρ = 0.001 / 0.999

Given:

E = 69 GPa = 69×10⁹ Pa

ν = 0.32

ΔP = 69×10⁹ Pa / (3 (1 - 2×0.32)) (0.001/0.999)

ΔP = 64.0×10⁶ Pa

If we assume seawater density is constant at 1027 kg/m³, then:

ρgh = P

(1027 kg/m³) (9.81 m/s²) h = 64.0×10⁶ Pa

h = 6350 m

Rounded to two sig-figs, the ocean depth at which the sphere's volume is reduced by 0.10% is approximately 6400 m.

6 0
3 years ago
Plz help
pogonyaev
Cells undergo cell division ( creates more cells to replace dead cells )
8 0
3 years ago
How does mass differ from weight? List 2 differences.
Alinara [238K]

weight is vector vary from place to place

5 0
3 years ago
Read 2 more answers
Tectonic plate movement is the reason why northern California has a very different landscape than southern California. Two diffe
Studentka2010 [4]

Answer:

I don't know the answer I need points before I fail my math test

3 0
2 years ago
Which of the following statements is true about static electricity?
natta225 [31]
Static electricity can be an alternating current.
3 0
2 years ago
Read 2 more answers
Other questions:
  • Please help with 3 questions about acceleration
    6·1 answer
  • As an apple falls from a tree, which types of energy are changing?
    9·1 answer
  • Two solid spheres, one of radius R and mass M, the other of radius 2R and mass 8M, roll down an incline. They start together fro
    14·1 answer
  • What change of state occurs during vaporization? liquid to gas gas to liquid solid to liquid liquid to solid
    8·2 answers
  • Light of the same wavelength passes through two diffraction gratings. One grating has 4000 lines/cm, and the other one has 6000
    7·1 answer
  • A pushing force acts on a toy car for 3 seconds causing it to accelerate at a rate A’. If the car is replaced with a similar, bu
    14·2 answers
  • Which of the following has the least resistance?<br><br> wood<br> iron<br> copper<br> silver
    15·1 answer
  • In which case would electrical potential energy be built up and stored in the electric field?
    13·1 answer
  • Since sound is a mechanical wave it needs a ...... to travel through
    5·1 answer
  • Help!!!!!!!!!!!!!!!!!​
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!