The correct answer to the question is 130.4 N.
CALCULATION;
The mass of the bullet is given as m = 28 gram = 0. 028 kg.
The initial velocity of the bullet u = 55 m/s
The final velocity of the bullet v = 18 m/s.
The distance covered by the bullet through the sand bag s = 29 cm.
= 0.29 m
Let the acceleration of the bullet is a .
From equation of kinematics, we know that-

⇒ 


The negative sign is used due to the fact that force is opposing in nature. Its velocity is decreasing with time.
From Newton's second law of motion, we know that net force on a body is equal to the product of mass with acceleration.
Mathematically F = ma.
Hence, the frictional force exerted on the bullet is calculated as -
F = m × a
= 0.028 × (-4656.897) N
= -130.4 N [ANS]
Here, N ( newton) stands for the unit of force.
It's called Throat. You can refer the figure attached.
Answer:
3.73 * 10^16 photons/sec
Explanation:
power supply = 3.0 V
Emits 440 nm blue light
current in LED = 11 mA
efficiency of LED = 51%
<u>Calculate the number of photons per second the LED will emit </u>
first step : calculate the energy of the Photon
E = hc / λ
=( 6.62 * 10^-34 * 3 * 10^8 ) / 440 * 10^-9
= 0.0451 * 10^-17 J
Next :
Number of Photon =( power supply * efficiency * current ) / energy of photon
= ( 3 * 0.51 * 11 * 10^-3 ) / 0.0451 * 10^-17
= 3.73 * 10^16 photons/sec
Answer:
Distance: -30.0 cm; image is virtual, upright, enlarged
Explanation:
We can find the distance of the image using the lens equation:

where:
f = 15.0 cm is the focal length of the lens (positive for a converging lens)
p = 10.0 cm is the distance of the object from the lens
q is the distance of the image from the lens
Solving for q,

The negative sign tells us that the image is virtual (on the same side of the object, and it cannot be projected on a screen).
The magnification can be found as

The magnification gives us the ratio of the size of the image to that of the object: since here |M| = 3, this means that the image is 3 times larger than the object.
Also, the fact that the magnification is positive tells us that the image is upright.