What is the magnitude of the tangential acceleration of a bug on
the rim of a 12.5-in.-diameter disk if the disk accelerates
uniformly from rest to an angular speed of 75.0 rev/min in 3.50
s?
m/s2
(b) When the disk is at its final speed, what is the magnitude of
the tangential velocity of the bug?
m/s
(c) One second after the bug starts from rest, what is the
magnitude of its tangential acceleration?
m/s2
(d) One second after the bug starts from rest, what is the
magnitude of its centripetal acceleration?
m/s2
(e) One second after the bug starts from rest, what is its total
acceleration? (Take the positive direction to be in the direction
of motion.)
| magnitude | m/s2 |
| direction | ° from the radially inward direction |
In: Physics
1. Explain the difference between an elastic and inelastic collision.
2. How many times more energy is required to increase the speed of a 2200 pound car by 10 mph if car initially is going 30 mph versus it initially going 80 mph? (convert to metric)
3. how many horse power are required to accelerate from 80 mph to 90 mph in 0.75 seconds? (tell me the average horsepower. 1 horsepower = 750 watts)
4. will a solid lead cylinder float or sink in mercury? why? (Pp= 11.34 g/cm^3, Hg= 13.53 g/cm^3)
5. how many centimeters of the lead cylinder would be submerged in the mercury if its dimensions are (radius = 5cm, height = 10cm)
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Identify and briefly describe the five key components of the “scientific method”
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uranium-235 is used in a nuclear power plant as fuel source because
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1)Two newly discovered planets follow circular orbits around a star in a distant part of the galaxy. The orbital speeds of the planets are determined to be 39.7 km/s and 53.7 km/s. The slower planet's orbital period is 8.02 years. (a) What is the mass of the star? (b) What is the orbital period of the faster planet, in years?
2)Two satellites are in circular orbits around the earth. The orbit for satellite A is at a height of 461 km above the earth’s surface, while that for satellite B is at a height of 881 km. Find the orbital speed for (a) satellite A and (b) satellite B.
3)The drawing shows a baggage carousel at an airport. Your suitcase has not slid all the way down the slope and is going around at a constant speed on a circle ((r = 14.0 m) as the carousel turns. The coefficient of static friction between the suitcase and the carousel is 0.570, and the angle θ in the drawing is 18.7°. How much time is required for your suitcase to go around once? Assume that the static friction between the suitcase and the carousel is at its maximum.
4) A satellite is in a circular orbit about the earth (ME = 5.98 x 1024 kg). The period of the satellite is 2.37 x 104 s. What is the speed at which the satellite travels?
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why does a satellite in a circular orbit travel at a constant speed (choose all that apply)
a. there is no force acting along the direction of motion of the
satellite
b. the only force is the force of gravity
c. there is no component of net force in the radial direction
d. the net force acting on the satellite is toward the center of
the path
e. There is a component of the net force acting in the direction of
the motion of the satellite
f. the gravitational force acting on the satellite is balanced by
the centrifugal force
(I know its not F bc centrifugal force its really a real thing but the rest... idk)
a box of mass 10 kg is pressed but not attached to an ideal spring compressing the spring a distance of 2.5cm after it is released the box slides up a frictionless incline and eventually stops at a vertical height h, the same experiment is repeated with the same box and spring but with an initial compression of 5cm the vertical height the box reaches the second time is ______
i'm thinking its 2x because its 2x the compression but let me know I might be very very wrong
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A manufacturer produces either edible honeycomb or honey from the raw honeycomb harvested from the beehives. To produce edible honeycomb, raw honeycomb is fed to a cutter that produces 30 edible combs per raw comb, and the manufacturer wants to produce 1200 edible combs an hour. The raw honeycomb that is to be made into honey is put through an uncapping and filter machine that separates both the wax and the honey from the frame. The honey is then split, part going to storage and part going to a heater which warms the honey before packaging.
If each raw honeycomb has a 1 pound frame, holds 7
pounds of honey, and has an average weight of 10 pounds, how much
wax is produced (lbs/hr) when 300 raw honeycombs/hour is fed to the
system?
How much extra honey (lbs/hr) must be stored to keep production at
1500 lbs/hr for the warm honey?
If honey enters the heater at 25°C and leaves at 55°C, how much
energy does the heater use (kW)?
Given information: Cp of honey:
1.9 + 28.8×10^-4 T + 6.4×10^-5 T^2 + 6.9×10^-8 T^3
Units of specific heat are Celsius.
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A block having a mass of 10.0 kg is pressed against the wall by a hand exerting a force F inclined at an angle θ of 52° to the wall as shown below. The coefficient of static friction µstat between the block and the wall is 0.20. We shall investigate the question of how large the force F must be to keep the block from sliding along the wall. There is more physics here than initially meets the eye. Think about the situation in terms of your everyday experience (or better yet, actually try it out): If you start out with a small value of F, the block will tend to slide downward; as you increase F, you reach the point at which the block will no longer slide; as you continue increasing F, the block stays put until, at some larger value of F, it might even begin to slide upward. This is the physics to be investigated, both algebraically and numerically.
(a) First draw well-separated force diagrams of the block and the region of the wall where the two are in contact (1) for the case in which F is small enough that the block tends to slide downward and (2) for the case in which the block tends to slide upward. Denote the various forces by appropriate algebraic symbols; do not put in numbers at this point. Describe each force in words and identify the third law pairs.
(b) Applying Newton’s second law, obtain algebraic expressions for F in terms of m, g, µstat, and θ for case 1, in which the block is just about to start sliding downward and for case 2, in which it is just about to start sliding upward.
(c) Now put in the various numbers and calculate the value of F for each of the two cases. How large is the spread between the two values? Does your result make physical sense? What is going on at the wall when F lies between the two extremes you have calculated? What happens to the frictional force when F lies between these two extremes?
(d) Return to the algebraic expression for case 2 in which the block is just about to slide upward. What does this expression say happens to F if you keep m and θ constant but increase the value of µstat? What is the equation telling us happens at the point at which µ is large enough to make the denominator of the expression equal to zero? Is it possible to make the block slide upward with a sufficiently large F at a fixed value of θ regardless of the value of µstat? Solve for the value of µstat at which it becomes impossible to make the block slide upward, showing that this value depends only on θ and is independent of the weight of the block. Do you find this result strange? Why or why not? Could you have anticipated it without having made the mathematical analysis?
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(c) Powder diffraction experiment:
The incident wavelength of a neutron beam is λ = 2.662 Å. The distance between adjacent atoms in a simple cubic crystal structure is 3.26 Å. Calculate the scattering angle of the 1st,
2nd and 3rd diffraction maximum. Up to which order ’n’ can the diffraction peaks be observed?
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A 15.0-L tank containing 1.0 mol of argon gas is at 298 K.
(a) Calculate the initial pressure of the gas and d, the length of the cube containing this volume.
(b) Using your value for d, calculate the energies of the two lowest translational energies for the system E1,1,1 and E2,1,1 and their differences ΔE .
(c) The tank is opened and the gas is allowed to expand rapidly into a cubical 2000L room such that there is no heat exchange with the surrounding.
Assuming n2,1,1/n1,1,1 remains constant, Determine the new temperature of the gas.
Handwritten answers are preferred.
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A proton, moving with a velocity of viî, collides elastically with another proton that is initially at rest. Assuming that after the collision the speed of the initially moving proton is 1.40 times the speed of the proton initially at rest, find the following.
(a) the speed of each proton after the collision in terms of vi
initially moving proton
initially at rest proton
(b) the direction of the velocity vectors after the collision (assume that the initially moving proton scatters toward the positive y direction)
initially moving proton
initially at rest proton
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Steam at 100°C is added to ice at 0°C.
(a) Find the amount of ice melted and the final
temperature when the mass of steam is 13.0 g and the mass
of ice is 45.0 g.
g
°C
(b) Repeat this calculation, when the mass of steam
as 1.30 g and the mass of ice is 45.0 g.
g
°C
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The sketch below is a free-body diagram (with all the forces shown) of a bridge. The distance are each 800 cm along the bottome of the bridge, "RL" to "A", "A" to "C", "C" to "B" and "B" to "R". The vertical height shown on the right side of the sketch is 1385 cm. The known forces are A= 5000 N, B= 3000 N and C= 10,000 N. You are to calculate the unknown reactions RLx, RLy and Rr.
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As a city planner, you receive complaints from local residents about the safety of nearby roads and streets. One complaint concerns a stop sign at the corner of Pine Street and 1st Street. Residents complain that the speed limit in the area (55 mph) is too high to allow vehicles to stop in time. Under normal conditions this is not a problem, but when fog rolls in visibility can reduce to only 155 ft. Since fog is a common occurrence in this region, you decide to investigate.
The state highway department states that the effective coefficient of friction between a rolling wheel and asphalt ranges between 0.689 and 0.770, whereas the effective coefficient of friction between a skidding (locked) wheel and asphalt ranges between 0.450 and 0.617.Vehicles of all types travel on the road, from small VW bugs weighing 1430 lb to large trucks weighing 9180 lb.
Considering that some drivers will brake properly when slowing down and others will skid to stop, calculate the minimum and maximum braking distance needed to ensure that all vehicles traveling at the posted speed limit can stop before reaching the intersection.
minimum braking distance: ft
maximum braking distance: ft
Given that the goal is to allow all vehicles to come safely to a stop before reaching the intersection, calculate the maximum desired speed limit.
maximum speed limit: mph
Which factors affect the soundness of your decision?
Drivers cannot be expected to obey the posted speed limit.
Reaction time of the drivers is not taken into account.
Precipitation from the fog can lower the coefficients of friction.
Newton's second law does not apply to this situation.
In: Physics
Consider three identical metal spheres, A, B, and C. Sphere A carries a charge of +2q. Sphere B carries a charge of +3q. Sphere C carries no net charge. Spheres A and B are touched together and then separated. Sphere C is then touched to sphere A and separated from it. Last, sphere C is touched to sphere B and separated from it. For the following questions, express your answers in terms of q.
(a) How much charge ends up on sphere C?
(b) What is the total charge on the three spheres before they are
allowed to touch each other?
(c) What is the total charge on the three spheres after they have
touched?
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