An equilateral triangle 7.0 m on a side has a m1 = 25.00 kg mass at one corner, a m2 = 85.00 kg mass at another corner, and a m3 = 115.00 kg mass at the third corner. Find the magnitude and direction of the net force acting on the 25.00 kg mass.

Hooke's Law

Objective: To verify Hooke’s law that the extension of a spring is proportional to the stretching force applied once the elastic limit is not exceeded.

1. a) Mention at least three important precautions that you take while performing the experiment? b)Give one example where Hooke’s law can be applied. c) Draw the forces experienced by the mass spring system. d) Name the forces and state the law applicable here. e)  If a mass of 250 grams is suspended, then find the values of these forces that you have mentioned. (Clear and Legible writing please and thank you)

Three children are riding on the edge of a merry-go-round that is 122 kg, has a 1.60 m radius, and is spinning at 15.3 rpm. The children have masses of 19.9, 29.0, and 38.8 kg. If the child who has a mass of 29.0 kg moves to the center of the merry-go-round, what is the new angular velocity in rpm?

Use the following data to determine the maximum rate at which a standard man can climb a mountain: Blood contains 16.0 wt% hemoglobin (with molecular weight 65,000 g/mol). Each hemoglobin molecule can carry four oxygen molecules. The heart pumps 101 cm³/s blood of density 1.06 g/cm³. Each oxygen molecule can oxidize one sugar unit (the chemical formula per sugar unit is CH₂O, which is an organic alcohol group) to CO₂ and H₂O; the oxidation of 1 g sugar yields about 17 kJ of energy, of which 25% can be used to do muscle work. (Assume the climber has a mass of 66 kg.)

A “friend” borrows your favorite compass and paints the entire needle red. You discover this when you are lost in a cave and have with you two flashlights, a few meters of wire, and (of course) your physics textbook. How might you discover which end of your compass needle is the north-seeking end?

A 100 g ball moving to the right at 4.0 m/s collides head-on with a 200 g ball that is moving to the left at 3.0 m/s.

If the collision is perfectly elastic, what are the speeds of each ball after the collision?

(Vfx)1 and (Vfx)2

What is the direction of 100-g ball after the collision? upward, downard, to the right, to the left?

What is the direction of 200-g ball after the collision? upward, downward, to the right, to the left?

If the collision is perfectly inelastic, what is the speed of the combined balls after the collision?

What is the direction of the combined balls after the collision? upward, downward, to the right, to the left?

A ball is held at rest at some height above a hard, horizontal surface. Once the ball is released it falls, hits the surface, and starts bouncing vertically up and down. Suppose that with each bounce the ball loses a fixed fraction p (with 1>p>0) of its energy. This loss could be due to a number of reasons (inelasticity, drag, etc) that are left unspecified.

1. How many times will the ball bounce before coming to rest (if at all)? Provide a detailed explanation of your reasoning, not simply a one-line answer.
2. How long will it take for the ball to come to rest (if at all)? Give your answer as a formula that contains as variables only p and the time T₁ from the moment that the ball was released to the first contact with the horizontal surface.

Answer should contain careful and detailed reasoning

An 80 kg man stands in a very strong wind moving at 15 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.

Part A

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.

Express your answer with the appropriate units.

For Part A. I tried 72.9 degrees, 85.02 degrees and 234.44 (I'm desperate)

Part B

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?

Express your answer in degrees.

For part B. I already tried 5.25 degrees, 5.5 degrees and 6.5 degrees

I need help please!!!!

A 144-g baseball moving 29 m/s strikes a stationary 5.25-kg brick resting on small rollers so it moves without significant friction. After hitting the brick, the baseball bounces straight back, and the brick moves forward at 1.21 m/s .

A)Determine the baseball's speed after the collision.

B)Determine the total kinetic energy before the collision.

C)Determine the total kinetic energy after the collision.

True or false: The quantity represented by ω0 is a function of time (i.e., is not constant).

True or false: The quantity represented by ω is a function of time (i.e., is not constant

Which of the following equations is not an explicit function of time t, that is, does not involve t as a variable, and is therefore useful when you do not know or do not need the time? θ=θ₀+ω₀t+(1/2)αt²

ω=ω₀+αt

ω²=ω₀²+2α(θ−θ₀)

In the equation ω=ω0+αt, what does the time variable t represent? Choose the answer that is always true. Several of the statements may be true in a particular problem, but only one is always true. Choose the answer that is always true. Several of the statements may be true in a particular problem, but only one is always true.

the moment in time at which the angular velocity equals ω0

the moment in time at which the angular velocity equals ω

the time elapsed from when the angular velocity equals ω0 until the angular velocity equals ω

Suppose you are asked to find the amount of time t, in seconds, it takes for the turntable to reach its final rotational speed. Which of the following equations could you use to directly solve for the numerical value of t? Suppose you are asked to find the amount of time , in seconds, it takes for the turntable to reach its final rotational speed. Which of the following equations could you use to directly solve for the numerical value of ?

θ=θ₀+ω₀t+(1/2)αt²

ω=ω₀+αt

ω²=ω₀²+2α(θ−θ₀)

More information is needed before t can be found.

You drop a steel ball bearing, with a radius of 3.40 mm, into a beaker of honey. Note that honey has a viscosity of 6.00 Pa/s and a density of 1360 kg/m3, and steel has a density of 7800 kg/m3. Assume that g = 9.8 m/s2. (a) What is the terminal speed of the ball bearing? m/s (b) Aluminum has a density of 2700 kg/m3. What radius should an aluminum ball have to have the same terminal speed in honey that the steel ball has?. mm

4) Mass 1 is initially moving at 3 m/s in the +x direction and it collides perfectly elastically with mass 2 moving at 10 m/s in the -x direction. After the collision, mass 1 is moving at 5 m/s in the +x direction. What is the final velocity of mass 2 in m/s? If in the negative x direction, include a negative sign. (Note: the masses are not needed to answer this question.)

A beam of light in air is incident at an angle of 24.0° to the surface of a rectangular block of clear plastic ( n = 1.46). The light beam first passes through the block and re-emerges from the opposite side into air at what angle to the normal to that surface?

Because movie producers have come under pressure for teaching children incorrect science, you have been appointed to help a committee of concerned parents review a script for a new Superman movie. In the scene under consideration, Superman rushes to save Lois Lane who has been pushed from a window 300 feet above a crowded street. Superman is 0.5 miles away when he hears Lois scream and rushes to save her. He swoops down in the nick of time, arriving when Lois is just 3.0 feet above the street, and stopping her just at ground level. Lois changes her expression from one of horror at her impending doom to a smile of gratitude as she gently floats to the ground in Superman's arms. The committee wants to know if there is really enough time to express this range of emotions, even if there is a possible academy award on the line. The chairman asks you to calculate the time it takes for Superman to stop Lois's fall. To do the calculation, you assume that Superman applies a constant force to Lois in breaking her fall and that she weighs 120 lbs. While thinking about this scene you also wonder if Lois could survive the force that Superman applies to her.