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
Mnenie [13.5K]
4 years ago
10

A 30 g bullet moving a horizontal velocity of 500 m/s comes to a stop 12 cm within a solid wall. (a) what is the change in the b

ullet's mechanical energy? (b) what is the magnitude of the average force from the wall stopping it?
Physics
1 answer:
Sidana [21]4 years ago
7 0
M = 30 g = 0.03 kg, the mass of the bullet
v = 500 m/s, the velocity of the bullet

By definition, the KE (kinetic energy) of the bullet is
KE = (1/2)*m*v²
      = 0.5*(0.03 kg)*(500 m/s)² = 3750 J
Because the bullet comes to rest, the change in mechanical energy is 3750 J.

The work done by the wall to stop the bullet in 12 cm is
W = (1/2)*(F N)*(0.12 m) = 0.06F J

If energy losses in the form of heat or sound waves are ignored, then
W = KE.
That is,
0.06F = 3750
F = 62500 N = 62.5 kN

Answer:
(a) 3750 J
(b) 62.5 kN

You might be interested in
An astronaut is traveling in a space vehicle that has a speed of 0.480c relative to Earth. The astronaut measures his pulse rate
Alexxandr [17]

Explanation:

The heart rate of the astronaut is 78.5 beats per minute, which means that the time between heart beats is 0.0127 min. This will be the time t measured by the moving observer. The time t' measured by the stationary Earth-based observer is given by

t' = \dfrac{t}{\sqrt{1 - \left(\dfrac{v^2}{c^2}\right)}}

a) If the astronaut is moving at 0.480c, the time t' is

t' = \dfrac{0.0127\:\text{min}}{\sqrt{1 - \left(\dfrac{0.2304c^2}{c^2}\right)}}

\:\:\:\:=0.0145\:\text{min}

This means that time between his heart beats as measured by Earth-based observer is 0.0145 min, which is equivalent to 69.1 beats per minute.

b) At v = 0.940c, the time t' is

t' = \dfrac{0.0127\:\text{min}}{\sqrt{1 - \left(\dfrac{0.8836c^2}{c^2}\right)}}

\:\:\:\:=0.0372\:\text{min}

So at this speed, the astronaut's heart rate is 1/(0.0372 min) or 26.9 beats per minute.

8 0
3 years ago
Which equation would you use to solve the following problem? An object is moved 29 m with a force of 289 N. What is the work don
Ksivusya [100]
Work, scientifically speaking, is done when a force is applied to an object which consequently moves the object at a certain direction. Work in formula, is force multiplied with distance.
 W = F x d
4 0
3 years ago
sticking your fingers into a wall socket will not bring you into direct contact with an electrical current. true or false
SCORPION-xisa [38]
The correct answer is false cause how can u fit your finger in a wall something it's to small
3 0
3 years ago
Read 2 more answers
Is gravity a field force
Alekssandra [29.7K]
Yes, it is because gravity is a force of attraction to the center of our planet, Earth. If we drop a pencil, the pencil will go on the floor. Gravity is pulling the pencil down. 
5 0
3 years ago
A person who normally weighs 580 N is riding in an elevator that is moving upward, but slowing down at a steady rate. If this pe
Zanzabum

Answer:

M au = Fs - M g       au = upwards acceleration; Fs = scale reading

Fs = M (au + g)    scalar quantities where g is positive downwards and au is positive upwards - Fs is the net force acting on the person

If the acceleration is zero Fs = M g  and the scale reads the persons weight

If the elevator is decelerating then au is negative and the scale reading     Fs = (g - au) M     and the scale reading is less than the weight of the person

5 0
2 years ago
Other questions:
  • Blood flow rates in the umbilical cord can be found by measuring the Doppler shift of the ultrasound signal reflected by the red
    10·1 answer
  • What is special about a DC circuit?
    6·2 answers
  • Formula for displacement
    15·1 answer
  • Scientific work is currently underway to determine whether weak oscillating magnetic fields can affect human health. For example
    14·1 answer
  • Which of the following statements is true? The melting and freezing points of a substance are the same. The melting and boiling
    12·2 answers
  • A starship is cruising the interstellar space with a velocity of 2174.799173 miles per second. How far would the starship have t
    7·1 answer
  • An electron moving at 2.97×103 m/s in a 1.25 T magnetic field experiences a magnetic force of 1.40×10−16 N . What angle (in degr
    8·1 answer
  • A glass rod acquires charge by rubbing silk cloth. The charge on the glass is due to:
    14·2 answers
  • An object with a mass of 30 kg moves at a rate of 15 m/S over distance of 10 m. 900 joules of work was done in 10 seconds. What
    14·1 answer
  • Please please help me :)
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!