Answer:
W = 30 N
Explanation:
Applying the summation of torques about the wedge for equilibrium, taking the clockwise direction as negative. Since the ruler is balanced horizontally about the wedge. Therefore, the summation of all torques acting about the wedge must be equal to zero.
<u>W = 30 N</u>
Answer:
Explanation:
<u>Displacement</u>
It is a vector that points to the final point where an object traveled from its starting point. If the object traveled to several points, then the individual displacements must be added as vectors.
The mail carrier leaves the post office and drives 2 km due north. The first displacement vector is
Then the carrier drives 7 km in 60° south of east. The displacement has two components in the x and y axis given by
Finally, he drives 9.5 km 35° north of east.
The total displacement is
The direction can be calculated with
It is possible to demonstrate that the maximum distance occurs when the angle at which the projectile is fired is
.
In fact, the laws of motions on both x- and y- directions are
From the second equation, we get the time t at which the projectile hits the ground, by requiring
, and we get:
And inserting this value into Sx(t), we find
And this value is maximum when
, so this is the angle at which the projectile reaches its maximum distance.
So now we can take again the law of motion on the x-axis
And by using
, we find the value of the initial velocity v0:
It seems reasonable to assume that the car is standing still while the sand is pouring in. Since its speed is zero, it has no momentum, and that won't change until it starts moving, no matter how much sand has been loaded onto it.
The wavelength of a sound wave is related to its frequency by the relationship:
where
f is the frequency
v is the speed of the wave
is the wavelength
The wave in our problem has wavelength of
and speed of
(this is the speed of sound in air), therefore its frequency is
And the period of the wave is equal to the reciprocal of its frequency:
