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
kifflom [539]
3 years ago
15

A car traveling at 20 m/s when the driver sees a child standing in the road. He takes 0.80 s to react, then steps on the brakes

and slows at 7.0 m/s2. How far does the car go before it stops?
Physics
1 answer:
mr Goodwill [35]3 years ago
3 0

When driver see the child standing on road his speed is 20 m/s

So here at that instant his reaction time is 0.80 s

He will cover a total distance given by product of speed and time

d_1 = v* t

d_1 = 20 * 0.8

d_1 = 16 m

now after this he will apply brakes with acceleration a = 7 m/s^2

so the distance covered before it stop is given by

v_f^2 - v_i^2 = 2 a d

0 - 20^2 = 2*(-7)*d_2

d_2 = 28.6 m

so the total distance covered by it

d = d_1 + d_2

d = 16 + 28.6 = 44.6 m

<em>so it will cover a total distance of 44.6 m</em>

You might be interested in
As Aubrey watches this merry-go-round for a total of 2 minutes, she notices the black horse pass by 15 times. What is the period
marishachu [46]
2 min = 120 sec

120/15 = 8

The black horse represents 8 seconds.
8 0
3 years ago
Read 2 more answers
Please Help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
arsen [322]

Answer:

Given that

speed u=4*10^6 m/s

electric field E=4*10^3 N/c

distance b/w the plates d=2 cm

basing on the concept of the electrostatices

now we find the acceleration b/w the plates  to find the horizontal distance traveled by the electron when it hits the plate.

acceleration a=qE/m=1.6*10^{-19}*4*10^3/9.1*10^{-31} =0.7*10^{15}=7*10^{14} m/s

now we find the horizontal distance traveled by electrons hit the plates

horizontal distance

X=u[2y/a]^{1/2}

=4*10^6[2*2*10^{-2}/7*10^{14}]^{1/2}

=3*10^{-2}= 3 cm

5 0
3 years ago
A spring with a force constant of 5.3 n/m has a relaxed length of 2.60 m. when a mass is attached to the end of the spring and a
olganol [36]
This is the equation for elastic potential energy, where U is potential energy, x is the displacement of the end of the spring, and k is the spring constant. 
<span> U = (1/2)kx^2 
</span><span> U = (1/2)(5.3)(3.62-2.60)^2 
</span> U = <span> <span>2.75706 </span></span>J
6 0
3 years ago
Anika asks Eva to roll a basketball and then a bowling ball to her. Which requires more force to roll, and why?
Contact [7]
The bowling ball will require more force to roll because it is more massive.
3 0
3 years ago
Read 2 more answers
When we get out of the bed on a very cold morning, we feel that the air of the room is cold. But when we come back after staying
S_A_V [24]

Answer:

This is because the air outside is always cooler than the air inside, so after staying outside your body adapts to the cold air, when you come back inside, the cold air is still in you which makes the room seem warmer.

4 0
3 years ago
Other questions:
  • A 1500-kg car locks its brakes and skids to a stop on a slippery horizontal road, leaving skid marks that are 15 m long. How muc
    5·1 answer
  • In a physics lab, light with a wavelength of 490 nm travels in air from a laser to a photocell in a time of 17.5 ns . When a sla
    11·1 answer
  • An egg is thrown nearly vertically upward from a point near the cornice of a tall building. It just misses the cornice on the wa
    8·1 answer
  • Which procedure allow you to determine the volume of an irregularly shaped object
    15·1 answer
  • A uniform steel rod of cross-sectional area A is attached to rigid supports and is unstressed at a temperature of 458F. The stee
    13·2 answers
  • The dielectric in a capacitor serves two purposes. It increases the capacitance, compared to an otherwise identical capacitor wi
    6·1 answer
  • The law of what energy states that energy cannot be created or destroyed
    14·2 answers
  • What is the relationship between PE+KE and total energy? Provide details/data from the simulation.
    10·1 answer
  • A car goes from a speed of 10m/s to 30m/s over 4s. If the car has a mass of 1000kg, How strong is the force pushing the car forw
    5·1 answer
  • 1. Compared to most other metals, what properties do the alkali metals have? А low melting points and high densities B low melti
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!