I'm trying to figure out if there is a word or term for this situation.1 AnswerWords & Wordplay3 months ago
A mass is undergoing simple harmonic motion. When its displacement is 0, it is at its equilibrium position. At that moment, its speed is _______ and its acceleration is _______.
A 3.0 g latex balloon is filled with 2.5 g of helium. When filled, the balloon is a 31-cm-diameter sphere. When released, the balloon accelerates upward until it reaches a terminal speed.
What is this speed? Assume an air density of 1.2 kg/m3 and a drag coefficient for sphere of 0.47.Physics2 years ago
Your low-flow showerhead is delivering water at 0.90×10−4m3/s, about 1.5 gallons per minute.
If this is the only water being used in your house, how fast is the water moving through your house's water supply line, which has a diameter of 0.021 m (about 3/4 of an inch)?
Compressing air to fill a scuba tank warms it up. A dive shop compensates by putting the tank in a tub of water, keeping the tank and the gas inside it at a constant temperature as it is filled.
W>0 and Q<0
What can you say about the relative magnitudes of W and Q?
A diver leaves the platform with her body straight. Her body is in a relatively slow rotation, with an angular speed of 4.0 rad/s. She then tucks into a pike position, with her body essentially folded in half. We can use a simple model to understand what happens next. First, model her 50 kg,1.8 m body as uniform. Next, assume that when she goes into a pike position, shown in (Figure 1), she really does fold her body exactly in half.
Part A: What is her initial moment of inertia?
Part B: What is her moment of inertia in the pike position?
Part C: What is her angular speed in the pike position?
As an object moves around, on which quantities does the change in its gravitational potential energy depend? Choose all that apply.?
Its change in speed
Its change in height
The path of the motion
An 82-kg painter stands on a long horizontal board 1.55 m from one end. This 27-kg board is uniform, 5.5 m long, and supported at each end by vertical posts.
A: What is the magnitude of the total force provided by both posts?
B: What is the magnitude of the force of the post nearest to the painter?
I know to do Part A but I am stuck on Part B. Can someone please help?
The towers holding small wind turbines are often raised and lowered for easy servicing of the turbine. (Figure 1) shows a 1000 kg wind turbine mounted on the end of a 24-m-long, 500 kg tower that connects to a support column at a pivot. A piston connected 3.0 m from the pivot applies the force needed to raise or lower the tower. At the instant shown, the wind turbine is being raised at a very slow, constant speed.
The lightweight wheel on a road bike has a moment of inertia of 0.097 kg⋅m2. A mechanic, checking the alignment of the wheel, gives it a quick spin; it completes 5 rotations in 1.8 s. To bring the wheel to rest, the mechanic gently applies the disk brakes, which squeeze pads against a metal disk connected to the wheel. The pads touch the disk 7.1 cm from the axle, and the wheel slows down and stops in 1.3 s.3 AnswersPhysics2 years ago
As you hold your leg in this position, the upper leg exerts a force on the lower leg at the knee joint. What is the magnitude of this force?
If you stand on one foot while holding your other leg up behind you, your muscles apply a force to hold your leg in this raised position. We can model this situation as in (Figure 1). The leg pivots at the knee joint, and the force that holds the leg up is provided by a tendon attached to the lower leg as shown. Assume that the lower leg and the foot have a combined mass of 3.2kg, and that their combined center of gravity is at the center of the lower leg.
The four wheels of a car are connected to the car's body by spring assemblies that let the wheels move up and down over bumps and dips in the road. When a 68 kg (about 150 lb) person sits on the left front fender of a small car, this corner of the car dips by about 1.2 cm (about 1/2 in).
If we treat the spring assembly as a single spring, what is the approximate spring constant?
We can model a pine tree in the forest as having a compact canopy at the top of a relatively bare trunk. Wind blowing on the top of the tree exerts a horizontal force, and thus a torque that can topple the tree if there is no opposing torque. Suppose a tree's canopy presents an area of 9.0 m2 to the wind centered at a height of 7.0 m above the ground. (These are reasonable values for forest trees.)
Part A: If the wind blows at 6.5 m/s, what is the magnitude of the drag force of the wind on the canopy? Assume a drag coefficient of 0.50 and the density of air of 1.2 kg/m3. Assume a drag coefficient of 0.50 and the density of air of 1.2 kg/m3.
Part B:What torque does this force exert on the tree, measured about the point where the trunk meets the ground?
When you stand quietly, you pivot back and forth a very small amount about your ankles. It's easier to maintain stability if you tip slightly forward, so that your center of gravity is slightly in front of your ankles. The 74 kg man shown in (Figure 1) is 1.8 m tall; his center of gravity is 1.0 m above the ground and, during quiet standing, is 5.5 cm in front of his ankles.