Answer:
Angular momentum, 
Explanation:
It is given that,
Radius of the axle, 
Tension acting on the top, T = 3.15 N
Time taken by the string to unwind, t = 0.32 s
We know that the rate of change of angular momentum is equal to the torque acting on the torque. The relation is given by :

Torque acting on the top is given by :

Here, F is the tension acting on it. Torque acting on the top is given by :





So, the angular momentum acquired by the top is
. Hence, this is the required solution.
We use the work formula to solve for the unknown in the problem. The formula for work is expressed as the product of the net force and the distance traveled by the object. We were given both the force and the distance so we can solve work directly.
Work = 250 N x 50 m = 12500 J
Thus, the answer is C.
Answer:
17.66 kPa
Explanation:
The volume of water in the swimming pool is the product of its dimensions
V = 30 * 8.7 * 1.8 = 469.8 cubic meters
Let water density
, and g = 9.81 m/s2 we can calculate the total weight of water in the swimming pool

The area of the bottom
A = 30 * 8.7 = 261 square meters
Therefore the pressure is its force over unit area
or 17.66 kPa
Answer:


Explanation:
Given:
Let mass of the particle B be, 
then the mass of particle A, 
Energy stored in the compressed spring, 
Now when the compression of the particles with the spring is released, the spring potential energy must get converted into the kinetic energy of the particles and their momentum must be conserved.
Kinetic energy:

.............................(1)
<u>Using the conservation of linear momentum:</u>

.............................(2)
Put the value of
from eq. (2) into eq. (1)

...........................(3)
<u>Now the kinetic energy of particle B:</u>



Put the value of
form eq. (3) into eq. (1):

<u>Now the kinetic energy of particle A:</u>
<u />
<u />
<u />
<u />

Answer:
y = y₀ (1 - ½ g y₀ / v²)
Explanation:
This is a free fall problem. Let's start with the ball that is released from the window, with initial velocity vo = 0 and a height of the window i
y = y₀ + v₀ t - ½ g t²
y = y₀ - ½ g t²
for the ball thrown from the ground with initial velocity v₀₂ = v
y₂ = y₀₂ + v₀₂ t - ½ g t²
in this case y₀ = 0
y₂2 = v t - ½ g t²
at the point where the two balls meet, they have the same height
y = y₂
y₀ - ½ g t² = vt - ½ g t²
y₀i = v t
t = y₀ / v
since we have the time it takes to reach the point, we can substitute in either of the two equations to find the height
y = y₀ - ½ g t²
y = y₀ - ½ g (y₀ / v)²
y = y₀ - ½ g y₀² / v²
y = y₀ (1 - ½ g y₀ / v²)
with this expression we can find the meeting point of the two balls