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
pav-90 [236]
3 years ago
12

A 7.80 g bullet moving at 530 m/s penetrates a tree trunk to a depth of 5.40 cm. (a) Use work and energy considerations to find

the average frictional force that stops the bullet. (b) Assuming the frictional force is constant, determine how much time elapses between the moment the bullet enters the tree and the moment it stops moving.
Physics
1 answer:
True [87]3 years ago
8 0

Answer:

a) F=20287.22N

b) t=2*10^-4s

Explanation:

E=1/2*m*v^2=0.5*7.8*10^-3kg*(530m/s)^2=1095.51J

The frictional force's work must be equal than the energy to stop the bullet.

So: W=F*d=F*0.054m=1095.51J, F=20287.22N

Considering the frictional force is constant, the bullet moves with constant aceleration.

a=F/m=20287.22N/7.8*10-2kg=2.6*10^6m/s^2

then d(t)=Vt-1/2*a*t^2,

5.4*10^-2m=530m/s*t-1.3*10^6m/s^2*t^2

I will calculate the time using the cuadratic formula:

\frac{-b+-\sqrt{b^{2}-4ac } }{2a}

with a=1.3*10^6, b=-530, c=5.4*10^-2

t=2*10^-4s

You might be interested in
What energy transformations take place when you eat a taco and then go for a jog
sesenic [268]

Answer:

Chemical to kinetic and thermal.

Explanation:

You would eat the food (chemical) than you would jog and move around (kinetic). While running your body would also give off heat (thermal).Than your body would sweat to cool itself down.

6 0
3 years ago
A manager at a local bank analyzed the relationship between monthly salary and three independent variables: length of service (m
Readme [11.4K]

Answer:

a

Explanation:

8 0
3 years ago
You are given the melting points of three unknown substances and are asked to predict which one is an ionic compound. You would
nikitadnepr [17]
The answer is <span>highest</span>
4 0
3 years ago
How does water get to the tops of the tallest trees against the force of gravity
alexira [117]
Water gets to the leaves in the tops of the tallest trees by something called the cohesion-tension theory. Water has two very unique properties called adhesion and cohesion. Cohesion is the tendency of water molecules to stick together with one another. The water sticks together, leaving no room for air, strengthening the "force" of the water going up the tree. The water also sticks to the sides of the xylem inside the tree. In addition to these properties, there are also the factors of negative and positive water potential. For more information, look up more details of the cohesion-tension theory. 
4 0
3 years ago
Read 2 more answers
A spring with spring constant 15.5 N/m hangs from the ceiling. A ball is suspended from the spring and allowed to come to rest.
Aloiza [94]

Answer:

A) 138.8g

B)73.97 cm/s

Explanation:

K = 15.5 Kn/m

A = 7 cm

N = 37 oscillations

tn = 20 seconds

A) In harmonic motion, we know that;

ω² = k/m and m = k/ω²

Also, angular frequency (ω) = 2π/T

Now, T is the time it takes to complete one oscillation.

So from the question, we can calculate T as;

T = 22/37.

Thus ;

ω = 2π/(22/37) = 10.5672

So,mass of ball (m) = k/ω² = 15.5/10.5672² = 0.1388kg or 138.8g

B) In simple harmonic motion, velocity is given as;

v(t) = vmax Sin (ωt + Φ)

It is from the derivative of;

v(t) = -Aω Sin (ωt + Φ)

So comparing the two equations of v(t), we can see that ;

vmax = Aω

Vmax = 7 x 10.5672 = 73.97 cm/s

6 0
3 years ago
Other questions:
  • A spring stores 10. joules of elastic potential
    11·2 answers
  • Frequency is deoted as hertz; hertz is a measurement of the _________ _____ __________ that a wave is occurring.
    13·1 answer
  • This equation is known as the ideal gas law, and it can be used to predict the behavior of many gases at relatively low pressure
    10·1 answer
  • Please helppp nowwwwww
    12·1 answer
  • (PLEASE HELP THANK YOU) A car is going 8 meters per second on an access road into a highway and then accelerates at 1.8 meters p
    15·1 answer
  • If you place a magnet under a clear dish, and sprinkle iron fillings over it, above what part of the magnet will most of the fil
    9·2 answers
  • A person hears the echo of his own voice from a distant hill after 2 seconds. How far away is the person from the hill, if the s
    14·1 answer
  • ) A 73-mH solenoid inductor is wound on a form that is 0.80 m long and 0.10 m in diameter. A coil having a resistance of is tigh
    6·1 answer
  • A ball rolls off a table and it traveling with a horizontal velocity of 2 m/s and 1 point
    15·2 answers
  • prove displacement of a body in nth second is given by the S=u+a/2(2n-1) where symbols have their usual meaning
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!