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
inna [77]
3 years ago
13

Two cars are heading towards one another. Car A is moving with an acceleration of aA = 4 m/s2. Car B is moving with an accelerat

ion of aB = -11 m/s2. The cars are initially at rest and separated by a distance d = 2900 m on the x-axis. In how many seconds does Car B reaches to Car A?
Physics
1 answer:
Paladinen [302]3 years ago
4 0

Answer:

Car B reaches car A in 19.7 s.

Explanation:

Hi there!

The equation of the position of an object moving in a straight line at constant acceleration is as follows:

x = x0 + v0 · t + 1/2 · a · t²

Where:

x = position of the object at time t.

x0 = initial position.

v0 = initial velocity.

t = time.

a = acceleration

When both cars meet, their positions are the same. At the meeting point:

position of car A = position of car B

xA = xB

x0A + v0A · t + 1/2 · aA · t² = x0B + v0B · t + 1/2 · aB · t²

Let´s place the origin of the frame of reference at the point where A is located. In that case x0A = 0 and x0B = 2900 m. Since both cars are initially at rest, v0A and v0B = 0. So, the equation gets reduced to this:

1/2 · aA · t² = x0B + 1/2 · aB · t²  

If we replace with the data we have and solve for t:

1/2 · 4 m/s² · t² = 2900 m - 1/2 · 11 m/s² · t²

2 m/s² · t² =  2900 m - 5.5 m/s² · t²

5.5 m/s² · t² + 2 m/s² · t² = 2900 m

7.5 m/s² · t² = 2900 m

t² = 2900 m / 7.5 m/s²

t = 19.7 s

Car B reaches car A in 19.7 s.

You might be interested in
The catapults on the uss george h.w. bush can launch aircraft from rest to a speed of 150 mph over a distance of 270 feet. find
vlabodo [156]
Hope this helps, have a great day ahead!

8 0
3 years ago
an 1150kg elevator moving down speeds up at a rate of 3.5m/s. what is the tension in the supporting cables?
gtnhenbr [62]

Answer:

The tension force in the supporting cables is 7245N

Explanation:

There are two forces acting on the elevator: the force of gravity pointing down (+) with magnitude (elevator mass) x (gravitational acceleration), and the tension force of the cable pointing up (-) with an unknown magnitude F. The net force is the sum of these forces:

F_{net} = F_g - F = m\cdot g - F\\

We are given the resulting acceleration along with the mass, i.e., we know the net force, allowing us to solve for F:

1150kg\cdot 3.5\frac{m}{s^2}= 1150kg \cdot 9.8\frac{m}{s^2}-F\\\implies F = 1150kg\cdot(9.8-3.5)\frac{m}{s^2}= 7245N

The tension force F in the supporting cables is 7245N


3 0
3 years ago
How does radiation help treat cancer?
sergejj [24]

Answer:

it cools down the cancer cells

Explanation:

The cancer cells are rapidly reproducing and when you cool it down it slows down the mutation/ reproduction process.

3 0
3 years ago
Read 2 more answers
What type of energy does the box have after it is done being pulled?
Ksivusya [100]
Assuming that the box is moving when it is being pulled, Work is done on the box.

So work is the Force times the distance

W=Fd

But what is work actually ? When something moves due to force over some change in distance, it have energy.

But where does this energy come from ? Does it magically appear ? The energy comes from the applied force onto the box.

So the energy have been transferred. And it’s like that throughout the universe

Now to save time, I’ll just tell you the answer: kinetic energy

:)
3 0
3 years ago
Define fundamental unit ? write its two example. ​
stealth61 [152]

the International System of Units, the fundamental units are: The meter (symbol: m), used to measure length. The kilogram (symbol: kg), used to measure mass. The second (symbol: s), used to measure time. The ampere (symbol: A), used to measure electric current.

8 0
3 years ago
Other questions:
  • A ball rolling across the floor at a velocity of 6.15 m/s [E] slows to rest in 1.00 minute. The
    6·1 answer
  • Select all numbers that are correctly rounded
    10·1 answer
  • By what factor does the sound intensity increase if the sound intensity level increases from 60 db to 61 db?
    6·1 answer
  • you are doing an experiment outside on a sunny day you find the temperature of some sand is 28 degress Celsius you also find the
    14·1 answer
  • A certain wire has a length l and a resistance r. It is stretched uniformly to a length of 2l. The resistance of the wire after
    12·1 answer
  • 112. A string, fixed on both ends, is 5.00 m long and has a mass of 0.15 kg. The tension if the string is 90 N. The string is vi
    13·1 answer
  • The specific heat capacity of oxygen is 918j/kg c. That means that it takes 918 J of energy to raise ____ kg of oxygen by 1 degr
    8·1 answer
  • -
    5·2 answers
  • Why is brainly so dumb? I am currently trying to get into my account right now, and even though I JUST changed it, it keeps sayi
    6·2 answers
  • The power of a bulb is 100 watt .what does it mean​
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!