Answer:
Final speed, v = 1.25 m/s
Explanation:
Given that,
Mass of skater A, 
Initial speed of skater A,
(x axis)
Mass of skater B, 
Initial speed of skater B,
(y axis)
It is mentioned that the two skaters collide and cling together. It is case of inelastic collision in which momentum remains conserved. Let V is the final speed of the couple. It is given by :





So, the final speed of the couple is 1.25 m/s. Hence, this is the required solution.
rotational kinetic energy of it's particles
Answer:
Answered
Explanation:
The girl whirling the ball should let go off ball when the ball is at a position such that tangent to the circle is in the direction of the target.
the tangent at any point in a circular path indicates the direction of velocity at that point. And the moment when the centripetal force is removed the ball will follow the tangential path at that moment.
Answer:
A. 181.24 N
Explanation:
The magnitude of hte electrostatic force between two charged objects is given by the equation

where
k is the Coulomb's constant
q1, q2 are the magnitudes of the two charges
r is the separation between the charges
In this problem, we have:
is the magnitude of the 1st charge
is the magnitude of the 2nd charge
r = 2.5 cm = 0.025 m is the separation between the charges
Therefore, the magnitude of the electric force is:

So, the closest answer is
A) 181.24 N
Answer: 1.14 N
Explanation :
As any body submerged in a fluid, it receives an upward force equal to the weight of the fluid removed by the body, which can be expressed as follows:
Fb = δair . Vb . g = 1.29 kg/m3 . 4/3 π (0.294)3 m3. 9.8 m/s2
Fb = 1.34 N
In the downward direction, we have 2 external forces acting upon the balloon: gravity and the tension in the line, which sum must be equal to the buoyant force, as the balloon is at rest.
We can get the gravity force as follows:
Fg = (mb +mhe) g
The mass of helium can be calculated as the product of the density of the helium times the volume of the balloon (assumed to be a perfect sphere), as follows:
MHe = δHe . 4/3 π (0.294)3 m3 = 0.019 kg
Fg = (0.012 kg + 0.019 kg) . 9.8 m/s2 = 0.2 N
Equating both sides of Newton´s 2nd Law in the vertical direction:
T + Fg = Fb
T = Fb – Fg = 1.34 N – 0.2 N = 1.14 N