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
Andreas93 [3]
3 years ago
5

It is claimed that if a lead bullet goes fast enough, it can melt completely when it comes to a halt suddenly, and all its kinet

ic energy is converted into heat via friction. Find the minimum speed of a lead bullet (initial temperature = 27.4 °C) for such an event to happen.
Physics
1 answer:
Amiraneli [1.4K]3 years ago
3 0

Answer:

354.72 m/s

Explanation:

m = mass of lead bullet

c = specific heat of lead = 128 J/(kg °C)

L = Latent heat of fusion of lead = 24500 J/kg

T_{i} = initial temperature = 27.4 °C

T_{f} = final temperature = melting point of lead =  327.5 °C

v = Speed of lead bullet

Using conservation of energy

Kinetic energy of bullet = Heat required for change of temperature + Heat of melting

(0.5) m v^{2} = m c (T_{f} - T_{i}) + m L\\(0.5) v^{2} = c (T_{f} - T_{i}) + L\\(0.5) v^{2} = (128) (327.5 - 27.4) + 24500\\(0.5) v^{2} = 62912.8\\v = 354.72 ms^{-1}

You might be interested in
Did I do these questions correctly?
SOVA2 [1]
Yes, they seem right to me.
4 0
3 years ago
A train travels due north in a straight line with a constant speed of 100 m/s. Another train leaves a station 2,881 m away trave
damaskus [11]

Answer:

The trains will collide at a distance 1660 m from the station

Explanation:

Let the train traveling due north with a constant speed of 100 m/s be Train A.

Let the train traveling due south with a constant speed of 136 m/s be Train B.

From the question, Train B leaves a station 2,881 m away (that is 2,881 m away from Train A position).

Hence, the two trains would have traveled a total distance of 2,881 m by the time they collide.

∴ If train A has covered a distance x m by the time of collision, then train B would have traveled (2881 - x) m.

Also,

At the position where the trains will collide, the two trains must have traveled for equal time, t.

That is, At the point of collision,

t_{A} = t_{B}

t_{A} is the time spent by train A

t_{B} is the time spent by train B

From,

Velocity = \frac{Distance }{Time }\\

Time = \frac{Distance}{Velocity}

Since the time spent by the two trains is equal,

Then,

\frac{Distance_{A} }{Velocity_{A} }  = \frac{Distance_{B} }{Velocity_{B} }

{Distance_{A} = x m

{Distance_{B} = 2881 - x m

{Velocity_{A} = 100 m/s

{Velocity_{B} = 136 m/s

Hence,

\frac{x}{100} = \frac{2881 - x}{136}

136(x) = 100(2881 - x)\\136x = 288100 - 100x\\136x + 100x = 288100\\236x = 288100\\x = \frac{288100}{236} \\x = 1220.76m\\

x≅ 1,221 m

This is the distance covered by train A by the time of collision.

Hence, Train B would have covered (2881 - 1221)m = 1660 m

Train B would have covered 1660 m by the time of collision

Since it is train B that leaves a station,

∴ The trains will collide at a distance 1660 m from the station.

7 0
3 years ago
On the coordinate plane below, draw the vector that goes from (0,0) to (2,3)
Vladimir [108]

Simply draw the vector with the given coordinates.

7 0
3 years ago
How many seconds will it take to travel 3,600 meters if your speed is 90 meters per second?
klio [65]
40

Because if you divide 3,600 by 90 it is equivalent to 40.

Hope this helps, have a blessed day :)
4 0
3 years ago
Which property of a substance is not affected by physical changes?
Leokris [45]
The answer is A. Reactivity

hope this helps
8 0
3 years ago
Other questions:
  • Two satellites are orbiting earth at different altitudes. Which satellite orbits at a higher speed v around earth?
    6·1 answer
  • What term is given to a substance that can dissolve in a particular liquid?
    12·2 answers
  • Slow-moving vehicles are prohibited from traveling on expressways or on roadways with a minimum posted speed limit greater than
    5·1 answer
  • What name is given to a process where a substance melts under pressure?​
    7·1 answer
  • Three positive charges A, B, and C, and a negative charge D are placed in a line as shown in the diagram. All four charges are o
    13·1 answer
  • What's the difference in a balanced force in an unbalanced force
    6·1 answer
  • A boy got out of a boat and as he
    9·1 answer
  • Gravitational Force
    14·1 answer
  • A 1100 kg car pushes a 1800 kg truck that has a dead battery. When the driver steps on the accelerator, the drive wheels of the
    7·1 answer
  • Craig Terrill has many _________. Press enter to interact with the item, and press tab button or down arrow until reaching the S
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!