Answer:
Explanation:
Moment of inertia of larger disk I₁ = 1/2 MR²
Moment of inertia of smaller disk I₂ = 1/2 m r ²
Initial angular velocity
We shall apply law of conservation of angular momentum .
initial total momentum = final angular momentum
I₁ X ωi = ( I₁ + I₂ )ωf
1/2 MR² x ωi = 1/2 ( m r² + MR² ) ωf
ωf = ωi / ( 1 + m r²/MR² )
Answer:
The gravitational force exerted on the object is 75 N (answer D)
Explanation:
Hi there!
The gravitational force is calculated as follows:
F = m · g
Where:
F = force of gravity.
m = mass of the object.
g = acceleration due to gravity (unknown).
For a falling object moving in a straight line, its height at a given time can be calculated using the following equation:
y = y0 + v0 · t + 1/2 · a · t²
Where:
y = position at time t.
y0 = initial position.
v0 = initial velocity.
t = time.
g = acceleration due to gravity.
Let´s place the origin of the frame of reference at the point where the object is released so that y0 = 0. Let´s also consider the downward direction as negative.
Then, after 2 seconds, the height of the object will be -30 m:
y = y0 + v0 · t + 1/2 · g · t²
-30 m = 0 m + 0 m/s · 2 s + 1/2 · g · (2 s)²
-30 m = 1/2 · g · 4 s²
-30 m = 2 s ² · g
-30 m/2 s² = g
g = -15 m/s²
Then, the magnitude of the gravitational force will be:
F = m · g
F = 5 kg · 15 m/s²
F = 75 N
The gravitational force exerted on the object is 75 N (answer D)
Have a nice day!
Answer:
pu = 1260.9kg/m^3
the density of the unknown liquid is 1260.9kg/m^3
Explanation:
The density of a liquid is inversely proportional to the volume (height) of object submerged in it.
High density liquid possess higher buoyant force preventing objects from submerging.
p ∝ 1/V ∝ 1/h
since V = Ah
pu/pw = hw/hu
pu = pwhw/hu
Where;
p = density
h = height submerged
pu and pw is the density of unknown liquid and water respectively
hu and hw is the height of object submerged in unknown liquid and water respectively
pw = 1000kg/m^3
hu = 4.6cm = 0.046m
hw = 5.8cm = 0.058m
Substituting the given values;
pu = 1000×0.058/0.046
pu = 1260.9kg/m^3
the density of the unknown liquid is 1260.9kg/m^3
Answer:
14160 kg/m^3
Explanation:
First of all, we need to find the volume of the cylinder.
The volume of the cylinder is given by:
where:
is the radius
is the height
Substituting, we find
And the density is given by
where m = 1 kg is the mass. Substituting, we find
Answer:
t = 2 s
Explanation:
As we know that fish is pulled upwards with uniform maximum acceleration
then we will have
here we know that maximum possible acceleration of so that string will not break is given as
now we have
now for such acceleration we can use kinematics
t = 2 s
