Density = (mass) / (volume)
4,000 kg/m³ = (mass) / (0.09 m³)
Multiply each side
by 0.09 m³ : (4,000 kg/m³) x (0.09 m³) = mass
mass = 360 kg .
Force of gravity = (mass) x (acceleration of gravity)
= (360 kg) x (9.8 m/s²)
= (360 x 9.8) kg-m/s²
= 3,528 newtons .
That's the force of gravity on this block, and it doesn't matter
what else is around it. It could be in a box on the shelf or at
the bottom of a swimming pool . . . it's weight is 3,528 newtons
(about 793.7 pounds).
Now, it won't seem that heavy when it's in the water, because
there's another force acting on it in the upward direction, against
gravity. That's the buoyant force due to the displaced water.
The block is displacing 0.09 m³ of water. Water has 1,000 kg of
mass in a m³, so the block displaces 90 kg of water. The weight
of that water is (90) x (9.8) = 882 newtons (about 198.4 pounds),
and that force tries to hold the block up, against gravity.
So while it's in the water, the block seems to weigh
(3,528 - 882) = 2,646 newtons (about 595.2 pounds) .
But again ... it's not correct to call that the "force of gravity acting
on the block in water". The force of gravity doesn't change, but
there's another force, working against gravity, in the water.
Answer:
I = 16.7kgm²
Explanation:
Since, Torque is given by,
\tau = F*r = I*\alpha
here, I = Moment of inertia = ??
\alpha = angular acceleration of wheel = a/r
F = tangential tension acting on the wheel = T
a = acceleration of bag of sand = 2.95 m/s^2
r = radius of wheel = d/2 = 120/2 = 60 cm = 0.60 m
from force balance on sand bag,
mg - T = m*a
T = m*(g-a)
m = mass of sand bag = 20 kg
So, I = T*r/\alpha = m*(g-a)*r/(a/r)
Using known values:
I = 20*(9.81 - 2.95)*0.60/(2.95/0.60) = 16.74
I = 16.7 kgm² = Moment of inertia of wheel experimentally
also, Moment of inertia of wheel theoretically(I') = M*r²
given, M = mass of wheel = 70 kg
I' = 70*0.60²= 25.2 kgm² = Moment of inertia of wheel theoretically
Answer: (D)
Explanation: just took the quiz and got a 100!
From the calculations, the speed of sound in this case is 16.9 m/s.
<h3>What is an echo?</h3>
The term echo has to do with the reflection of sound waves. Sound is a mechanical wave.
we know that the speed of sound is obtained from;
V = 2x/t
x = distance covered
t = time taken
V = 2(500)/59
v = 16.9 m/s
The error in the experiment could come from;
- Lack of precise time measurement
- Error can also arise from the environment of the experiment
Learn more about echo:brainly.com/question/9527413
#SPJ1
Answer:
mucilage can detect objects the size of millimeters, whereas humans can only detect objects larger than centimeters
Explanation:
The human ear can detect sound in the range of 20 to 20000hz, we are asked to find the mid-range wavelength of the ear at f = 10000 Hz
let's use the relationship between wave speed, wavelength and frequency
v = λ f
λ= v / f
λ = 343/10000
λ = 3.43 10⁻² m
the sound range of a bat is between 25 10³ Hz and 100 10³ Hz, they also ask for the wavelength in the middle range
f = (100 10³ + 25 10³) / 2
f = 62.5 10³ Hz
λ = 343 / 62.5 10³
λ = 5.5 10⁻³ m
Therefore the size of the object that a bat can detect is much smaller than the size that a human can detect, therefore the bat is capable of detecting insects, but humans.
The mucilage can detect objects the size of millimeters, whereas humans can only detect objects larger than centimeters
