Since the stone was dropped from height, its initial velocity = 0 m/s
Using v² = u² + 2gs.
Where g ≈ 10 m/s², u = initial velocity = 0 m/s, s = height from drop = 2.5 m
v² = u² + 2gs
v² = 0² + 2*10*2.5
v² = 0 + 50
v² = 50
v = √50
v ≈ 7.07 m/s
Hence velocity just before hitting the ground is ≈ 7.07 m/s
Answer:
480J
Explanation:
Using the formula:
Delta U = Q - W
Q:Heat (J)
Delta U: Changes in internal Energy (J)
W:Work (J)
We can plug in the give numbers, Q and W.
Delta U = 658J - 178J = 480J
Answer:
Time, t = 80 seconds
Explanation:
Given that,
The frequency of the oscillating mass, f = 1.25 Hz
Number of oscillations, n = 100
We need to find the time in which it makes 100 oscillations. We know that the frequency of an object is number of oscillations per unit time. It is given by :
t = 80 seconds
So, it will make 100 oscillations in 80 seconds. Hence, this is the required solution.
Answer:
A) = 1.44 kg m², B) moment of inertia must increase
Explanation:
The moment of inertia is defined by
I = ∫ r² dm
For figures with symmetry it is tabulated, in the case of a cylinder the moment of inertia with respect to a vertical axis is
I = ½ m R²
A very useful theorem is the parallel axis theorem that states that the moment of inertia with respect to another axis parallel to the center of mass is
I = + m D²
Let's apply these equations to our case
The moment of inertia is a scalar quantity, so we can add the moment of inertia of the body and both arms
= + 2
= ½ M R²
The total mass is 64 kg, 1/8 corresponds to the arms and the rest to the body
M = 7/8 m total
M = 7/8 64
M = 56 kg
The mass of the arms is
m’= 1/8 m total
m’= 1/8 64
m’= 8 kg
As it has two arms the mass of each arm is half
m = ½ m ’
m = 4 kg
The arms are very thin, we will approximate them as a particle
= M D²
Let's write the equation
= ½ M R² + 2 (m D²)
Let's calculate
= ½ 56 0.20² + 2 4 0.20²
= 1.12 + 0.32
= 1.44 kg m²
b) if you separate the arms from the body, the distance D increases quadratically, so the moment of inertia must increase
(a) The distance of the image formed by the concave mirror is 19.1 cm.
(b) The image formed is diminished and real.
<h3>
Image distance </h3>
The distance of the image formed by the concave mirror is calculated as follows;
1/f = 1/v + 1/u
1/v = 1/f - 1/u
1/v = 1/15 - 1/70
1/v = 0.05238
v = 1/0.05238
v = 19.1 cm
The image distance is smaller than object distance, thus the image formed is diminished and real.
Learn more about concave mirror here: brainly.com/question/13164847
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