Answer:


Explanation:
Here mass density of rod is varying so we have to use the concept of integration to find mass and location of center of mass.
At any distance x from point A mass density


Lets take element mass at distance x
dm =λ dx
mass moment of inertia

So total moment of inertia

By putting the values

By integrating above we can find that

Now to find location of center mass


Now by integrating the above


So mass moment of inertia
and location of center of mass 
Use Newton's second law F = mass * acceleration
In your problem F = 500, and we know gravity is working on it so use a = 9.81
Substitute into the equation
500 = m * 9.81
m = 50.97 kg
C is the answer because it mix and water combining together
Given that,
The acceleration of gravity is -9.8 m/s²
Initial velocity, u = 39.2 m/s
Time, t = 2 s
To find,
The final velocity of the shot.
Solution,
Let v is the final velocity of sling shot. Using first equation of motion to find it.
v = u +at
Here, a = -g
v = u-gt
v = (39.2)-(9.8)(2)
v = 19.6 m/s
So, its velocity after 2 seconds is 19.6 m/s.
Answer:
the number density of the protons in the beam is 3.2 × 10¹³ m⁻³
Explanation:
Given that;
diameter D = 2.0 mm
current I = 1.0 mA
K.E of each proton is 20 MeV
the number density of the protons in the beam = ?
Now, we make use of the relation between current and drift velocity
I = MeAv ⇒ 1 / eAv
The kinetic energy of protons is given by;
K = 
v²
v = √( 2K /
)
lets relate the cross-sectional area A of the beam to its diameter D;
A =
πD²
now, we substitute for v and A
n = I /
πeD² ×√( 2K /
)
n = 4I/π eD² × √(
/ 2K )
so we plug in our values;
n = ((4×1.0 mA)/(π(1.602×10⁻¹⁹C)(2mm)²) × √(1.673×10⁻²⁷kg / 2×( 20 MeV)(1.602×10⁻¹⁹ J/ev )
n = 1.98695 × 10¹⁸ × 1.6157967 × 10⁻⁵
n = 3.2 × 10¹³ m⁻³
Therefore, the number density of the protons in the beam is 3.2 × 10¹³ m⁻³