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
Delicious77 [7]
3 years ago
10

A block is released to slide down a frictionless incline of 15∘ and then it encounters a frictional surface with a coefficient o

f kinetic friction μk = 0.16
A)Choose the appropriate Conservation of Energy equation used to find the horizontal distance traveled on the frictional surface before the block stops if the length of the incline (d) is known.

Which is PEg+Work=0


Need help on B.

B)Find the position where the block stops on the horizontal frictional surface is the block has a mass of 25 kg and the length of the incline is 20.4 m .

d=_____m
Physics
1 answer:
Elodia [21]3 years ago
5 0

The block's potential energy at the top of the incline (at a height h from the horizontal surface) is equal to its kinetic energy at the bottom of the incline, so that

mgh = 1/2 mv²

where v is its speed at the bottom of the incline. It follows that

v = √(2gh)

If the incline is 20.4 m long, that means the block has a starting height of

sin(15°) = h/(20.4 m)   ⇒   h = (20.4 m) sin(15°) ≈ 5.2799 m

and so the block attains a speed of

v = √(2gh) ≈ 10.1728 m/s

The block then slides to a rest over a distance d. Kinetic friction exerts a magnitude F over this distance and performs an amount of work equal to Fd. By the work-energy theorem, this quantity is equal to the block's change in kinetic energy, so that

Fd = 0 - 1/2 mv²   ⇒   d = (-1293.58 J)/F

By Newton's second law, the net vertical force on the block as it slides is

∑ F [vertical] = n - mg = 0

where n is the magnitude of the normal force, so that

n = mg = (25 kg) g = 245 N

and thus the magnitude of friction is

F = -0.16 (245 N) = -39.2 N

(negative since it opposes the block's motion)

Then the block slides a distance of

d = (-1293.58 J) / (-39.2 N) ≈ 32.9994 m ≈ 33 m

You might be interested in
What factors in Earth's relationship to the Sun make life on Earth possible?
Mila [183]
The answer is B.

The planet cannot be too hot or too cold it has to be the right distance from its sun to maintain life. 
5 0
3 years ago
Read 2 more answers
What is emitted during fission
krok68 [10]
Prompt gamma rays are....
5 0
3 years ago
What is the net force needed to accelerate a 21.4 kg grocery sack upward at 1.5 m/s2?
marshall27 [118]

Answer:

32.1 N Please Give Brainliest

Explanation:

force = mass x acceleration

8 0
2 years ago
Little Billie has a mass of 25 kg. The acceleration of gravity on the moon is one-sixth of the value on Earth. What is Little Bi
sineoko [7]

Answer:

Mass is constant everywhere,

But weight is different,

If earth g = 10 then moon's is 1.6666667

Now billie's weight in moon is 41.6667

6 0
3 years ago
Why is a concave mirror is used a reflector in a torch light?​
tatiyna

Answer:

diverging light rays of the bulb are collected by the reflector.

Explanation:

4 0
3 years ago
Read 2 more answers
Other questions:
  • A circuit has a voltage drop of 120 V across an 80 resistor that carries a current of 0.75 A. How much power is used by the resi
    7·1 answer
  • What is the acceleration of a skier that goes from 2.50 m/s to 14.5 m/s while traveling 505 m down a slope?
    10·1 answer
  • How are the planet's mercury and earth similar?
    5·2 answers
  • A book on a 2 meter high shelf has 20 Joules of potential energy.
    11·1 answer
  • How did world cup soccer become cool?
    5·1 answer
  • When divided by △t, (vf - vi) is used to determine which characteristic? A.Speed B.Direction C. Displacement D.Acceleration
    10·1 answer
  • A bucket of warm water can be considered a closed system for a very short period of time. Which best explains this phenomenon? A
    9·1 answer
  • Why is the Big Bang a theory and not a fact
    15·2 answers
  • What best defines work?
    11·1 answer
  • 1.do materials change when light is reflected off to them
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!