Sound waves travel faster through <em>solids</em> than they do through gases or liquids. <em>(C) </em>They don't travel through vacuum at all.
Example:
Speed of sound in normal air . . . around 340 m/s
Speed of sound in water . . . around 1,480 m/s
Speed of sound in iron . . . around 5,120 m/s
A). very large
B). very small
These are both wishy-washy words ... words that mean different things
to different people, and may even mean different things to the same person
at different times.
Even if everybody agreed on the meaning of these words, we wouldn't
have any idea which one may apply to the rover, because there's nothing
in the picture that gives any size reference ! We don't know from the picture
whether this thing is the size of a school book or a school bus. Or somewhere
in between.
C). very mathematical
What in the world does this mean ? ?
I don't see a single number or math symbol anywhere in the drawing.
I don't think this is the correct choice.
D). very complex
In the drawing, there are thirteen different labels of things,
and eight of them have such long names that only their initials
are shown.
This is one complicated combination of many different machines.
I think this is the best choice of description.
Answer:
4.535 N.m
Explanation:
To solve this question, we're going to use the formula for moment of inertia
I = mL²/12
Where
I = moment of inertia
m = mass of the ladder, 7.98 kg
L = length of the ladder, 4.15 m
On solving we have
I = 7.98 * (4.15)² / 12
I = (7.98 * 17.2225) / 12
I = 137.44 / 12
I = 11.45 kg·m²
That is the moment of inertia about the center.
Using this moment of inertia, we multiply it by the angular acceleration to get the needed torque. So that
τ = 11.453 kg·m² * 0.395 rad/s²
τ = 4.535 N·m
Answer:
0 Newtons
Explanation:
The velocity of the object does not change, it is a constant 54 km/hr. When velocity does not change, acceleration is zero. Using the formula Force = mass x acceleration, we find:
mass = 1200 kg
acceleration = 0
F = (1200)(0) = 0
