Steve Scoville

Numerade Educator
Teacher

Biography

Big believer in knowing WHY stuff works, not just THAT it works.

Education

Steve has not yet added their education credentials.

Educator Statistics

Numerade tutor for 4 years
5 Students Helped

Topics Covered

Mastering Motion: Achieving Efficiency Along a Straight Line
Mastering Newton's Laws: Tips for Applying Them Effectively

Steve's Textbook Answer Videos

1

Steve's Quick Ask Videos

33:16
Physics 101 Mechanics

As shown in the figure below, a uniform beam is supported by a cable at one end and the force of friction at the other end. The cable makes an angle of θ = 30°, the length of the beam is L = 5.00 m, the coefficient of static friction between the wall and the beam is μs = 0.540, and the weight of the beam is represented by w. Determine the minimum distance x from point A at which an additional weight 2w (twice the weight of the rod) can be hung without causing the rod to slip at point A.
x =

Since this is an equilibrium problem, we expect to use the first and second conditions for translational and rotational equilibrium, respectively, to solve the problem. Before starting the problem, a well-drawn figure with all forces and all forces resolved into components would be a real asset to finding a solution. See if you can use the first condition of equilibrium to obtain an expression for the normal force and then the force of friction. Next, see if you can use the first condition of equilibrium to obtain an expression for the tension in the cable. Finally, see if you can use the second condition of equilibrium to obtain an expression that will allow you to determine the maximum distance you can hang the weight from the end of the beam supported by the wall.

Steve Scoville
28:04
Physics 101 Mechanics

A stick is resting on a concrete step with 2/7 of its
total length 𝐿 hanging over the edge. A single ladybug
lands on the end of the stick hanging over the edge, and the stick
begins to tip. A moment later, a second, identical ladybug lands on
the other end of the stick, which results in the stick coming
momentarily to rest at 𝜃=67.3∘ with respect to the
horizontal, as shown in the figure.
If the mass of each bug is 3.09 times the mass of the stick
and the stick is 17.5 cm long, what is the
magnitude 𝛼 of the angular acceleration of the stick at
the instant shown? Use 𝑔=9.81 m/s2.
𝛼=_________ rad/s2

Steve Scoville
10:45
Physics 101 Mechanics

An 80 kg man stands in a very strong wind moving at 13 m/s at
torso height. As you know, he will need to lean in to the wind, and
we can model the situation to see why. Assume that the man has a
mass of 80 kg, with a center of gravity 1.0 m above the ground. The
action of the wind on his torso, which we approximate as a cylinder
50 cm wide and 90 cm long centered 1.2 m above the ground, produces
a force that tries to tip him over backward. To keep from falling
over, he must lean forward.
What is the magnitude of the torque provided by the wind force?
Take the pivot point at his feet. Assume that he is standing
vertically. Assume that the air is at standard temperature and
pressure. (the answer to this is 60 N*m)
At what angle to the vertical must the man lean to provide a
gravitational torque that is equal to this torque due to the wind
force?

Steve Scoville
04:47
Physics 101 Mechanics

Its a video of a glider pushed forward and going back
due to a fan blowing of the opposite direction of being
pushed.
After watching this video, Blake, a student in an introductory
physics class, makes the following claim:
The acceleration and velocity of the glider are both
momentarily zero when the glider changes direction. The velocity of
the glider must be zero for an instant when the glider changes
direction. Because the velocity is zero, the acceleration must also
be zero.
Respond to Blake's claim. Which parts, if any do you agree with,
and which parts do you not agree with? To support your response,
use evidence from your experience, or from the videos in this
activity.

Steve Scoville
05:09
Physics 101 Mechanics

A sailboat is traveling to the right when a gust of wind causes the boat to accelerate leftward at 2.5 m/s^2 for 4s. After the wind stops, the sailboat is traveling to the left with a velocity of 3.0 m/s. Assuming the acceleration from the wind is constant, what was the initial velocity of the sailboat before the gust of wind?

Steve Scoville
1