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
Zinaida [17]
3 years ago
14

In an emergency, a driver brings a car to a full stop in 5.0s. The car is traveling at a rate of 38m/s when the breaking begins.

Physics
1 answer:
Lana71 [14]3 years ago
6 0

(a) By definition of average acceleration,

<em>a</em> = ∆<em>v</em> / ∆<em>t</em> = (0 - 38 m/s) / (5.0 s)

<em>a</em> = -7.6 m/s²

(b) Recall that

<em>v</em>² - <em>u</em>² = 2 <em>a</em> ∆<em>x</em>

where <em>u</em> and <em>v</em> are initial and final velocities, respectively; <em>a</em> is acceleration; and ∆<em>x</em> is the change in position. So

0² - (38 m/s)² = 2 (-7.6 m/s²) ∆<em>x</em>

∆<em>x</em> = 95 m

You might be interested in
A brick lands 10.1 m from the base of a building. If it was given an initial velocity of 8.6 m/s [61º above the horizontal], how
Montano1993 [528]
<h2>Answer: 10.52m</h2><h2 />

First, we have to establish the <u>reference system</u>. Let's assume that the building is on the negative y-axis and that the brick was thrown at the origin (see figure attached).

According to this, the initial velocity V_{o} has two components, because the brick was thrown at an angle \alpha=61\º:

V_{ox}=V_{o}cos\alpha   (1)

V_{ox}=8.6\frac{m}{s}cos(61\º)=4.169\frac{m}{s}  (2)

V_{oy}=V_{o}sin\alpha   (3)

V_{oy}=8.6\frac{m}{s}sin(61\º)=7.521\frac{m}{s}   (4)

As this is a projectile motion, we have two principal equations related:

<h2>In the x-axis: </h2>

X=V_{ox}.t  (5)

Where:

X=10.1m is the distance where the brick landed

t is the time in seconds

If we already know X and V_{ox}, we have to find the time (we will need it for the following equation):

t= \frac{X}{ V_{ox}}  (6)

t=2.42s  (7)

<h2>In the y-axis: </h2>

-y=V_{oy}.t+\frac{1}{2}g.t^{2}   (8)

Where:

y is the height of the building (<u>in this case it has a negative sign because of the reference system we chose)</u>

g=-9.8\frac{m}{s^{2}} is the acceleration due gravity

Substituting the known values, including the time we found on equation (7) in equation (8), we will find the height of the building:

-y=(7.521\frac{m}{s})(2.42s)+\frac{1}{2}(-9.8\frac{m}{s^{2}}).(2.42s)^{2}   (9)

-y=-10.52m   (10)

Multiplying by -1 each side of the equation:

y=10.52m >>>>This is the height of the building

3 0
3 years ago
If a 2kg ball rolls down a ramp that is 15 meters long in 25 seconds, what is the
77julia77 [94]

Answer:

1.968504 ft/s

7 0
2 years ago
The force that acts on an object lying on a surface, acting in a direction perpendicular to the surface is called ____________​
DanielleElmas [232]
If it is on land gravitational force
If it is on water thrust
8 0
2 years ago
What is known as the amount of mass in
k0ka [10]
I believe the answer is D. Have a good day.
7 0
2 years ago
Read 2 more answers
NEED HELP ASAP!!!!!!!!!!
stepan [7]

Answer:

*The same balloon put into the freezer would be smaller and shriveled.

* The volume decreases as the temperature decreases.

* using a hypothetical starting volume of 2 liters in the balloon at 42 degrees Celsius, we can use the equation V1/T1 =V2/T2

V2= 1.54 liters which proves when temperature decreases , volume decreases as well.

Explanation:

The volume increases as the temperature increases, and volume decreases as the temperature decreases.

using a hypothetical starting volume of 2 liters in the balloon at 42 degrees Celsius, we can use the equation V1/T1 =V2/T2

Change Celsius to kelvin by adding 273.

2 liters/ 315 K = V2/243 K

Cross multiply and then divide by 315 to find V2

2 liters x 243 K / 315 K = V2

The Kelvin cancels itself out.

486 liters /315=V2

V2= 1.54 liters.

This proves that when the temperature decreases , so does the volume.

3 0
2 years ago
Other questions:
  • A firefighter with a weight of 756 N slides down a vertical pole with an acceleration of 2.96 m/s2, directed downward. What are
    15·1 answer
  • Which of the following foods contains large amounts of protein? chicken, beans, fish, dairy, berries
    15·2 answers
  • A skateboarder with mass ms = 54 kg is standing at the top of a ramp which is hy = 3.3 m above the ground. The skateboarder then
    14·1 answer
  • What are tiny sacs at the end of the bronchioles filled with air called?
    13·1 answer
  • What was the experiment carried out by Hershel &amp; Ritter.
    13·1 answer
  • Celine has raised the temperature of water to 100°C in order to cook pasta for her lasagna. What physical property is Celine dem
    14·1 answer
  • Help me please I can't get the final step​
    12·1 answer
  • Scientists plan to release a space probe that will enter the atmosphere of a gaseous planet. The temperature of the gaseous plan
    6·1 answer
  • Hey guys can you help me solve this problem "how long will it take a car travelling 30m/s to come to stop ifs its acceleration i
    11·1 answer
  • Most interstellar clouds are: Most interstellar clouds are: much bigger than our solar system. similar in size to clouds in Eart
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!