74,851 results, page 58
1. ## physics

An elevator is moving upward at 1.20 m/s when it experiences an acceleration 0.25 m/s2 downward, over a distance of 0.71 m. What will its final velocity be?
2. ## physics help!

Using the Bohr model, estimate the wavelength ë of the Ká characteristic X-ray for a metal an atom of which contains Z = 50 protons.
3. ## physics

Using the Bohr model, estimate the wavelength ë of the Ká characteristic X-ray for a metal an atom of which contains Z = 50 protons.
4. ## Physics

In a hydrogen atom, if the radius of the orbit of the electron is doubled, then its energy will ... >> Increase by a factor of 2??
5. ## physics

George takes off for a long jump at an angle of 28 degrees, and lands 6.9 m away. How fast was he when he jumped?
6. ## physics

Radio waves transmitted through space at 3.00¡¿10 8 m/s by the Voyager spacecraft have a wavelength of 0.120 m. What is their frequency?
7. ## physics

If your boat weighs 1600 N, how much water will it displace when it’s floating motionless at the surface of a lake?
8. ## Physics

What net external force is required to give a 30 kg suitcase an acceleration of 2.5 m/s2 to the right? Answer in units of N
9. ## physics

What is the magnitude of F? Assume the acceleration due to gravity is 9.8 m/s 2 and the surface is frictionless. Answer in units of N.
10. ## physics

A rock is dropped from a height of 130.0 meters. With what velocity does it land? How long does it take to fall?
11. ## Physics/ optics

An object is located 25cm in front of a +6.00 lens, where is the image? is it real or virtual?
12. ## Physics

A boy sledding down a hill accelerates at 1.25 m/s2. If he started from rest, in what distance would he reach a speed of 5.00 m/s?
13. ## college physics

How many seconds would it take a 7.00hp motor to raise a 475 lb boiler to a platform 38.0 ft high?
14. ## Physics

An elevator is moving upward at 0.90 m/s when it experiences an acceleration 0.40 m/s2 downward, over a distance of 0.64 m. What will its final velocity be?
15. ## physics

For a simple 15 upward ramp, what length would be needed for a runaway truck traveling 140 ?
16. ## Physics

A boy sledding down a hill accelerates at 1.25 m/s2. If he started from rest, in what distance would he reach a speed of 5.00 m/s?
17. ## college physics

how long would it take a 4.50kW MOTOR TO RAISE A 175KG BOILER TO A PLATFORM 15.0M ABOVE THE FLOOR?
18. ## AP Physics B

What is the force of Friction as a 12 kg object slides down for 30 meters down a 30 degrees incline at a constant velocity?
19. ## Physics

a boat sails 150km N60°E, then 100km West. What is it's displacement from its starting point?
20. ## Physics check

Atoms whose nuclei have the same number of protons but different numbers of neutrons are called.... isotopes?
21. ## mathematical method of physics

expand 3sin(4x)+4cos(10x) in to functional series of e(exp)ix
22. ## Physics

A 2473 kg elephant is walking at 3 m/s on a flat surface. How much kinetic energy does he have? Answer in Joules or J
23. ## physics

How high will an object rise if it is projected upward at a 45 degree angle and an initial velocity of 50 m/s?

You want to show that V^2 - Vo^2 = 2 a (X - Xo) first rewrite that as: (V-Vo)(V+Vo) = 2a (X-Xo) now your average velocity during the interval = (V+Vo)/2 so X = Xo + t(V+Vo)/2 but V = Vo + a t so t = (V-Vo)/a so X = Xo +(V-Vo)(V+Vo)/2a we are there.
25. ## Physics

A 6.25 kg solid ball with a radius of 0.185 m rolls without slipping at 3.55 m/s. What is its total kinetic energy?
26. ## Physics

A 2473 kg elephant is walking at 3 m/s on a flat surface. How much kinetic energy does he have? Answer in Joules
27. ## Physics

If the fundamental frequency of an 70 cm long guitar string is 470 Hz, what is the speed of the traveling waves?
28. ## Physics

How could you use the spotlights at a play to make the yellow clothes of the performers suddenly change to black?
29. ## physics

a car is moving at 17.7 m/s when it begins to slow down with a deceleration of 2.5 m/s2. how long does it take to travel 20 meters as it slows down
30. ## ap physics

How fast would a 1200 kg car travel if it had the same linear momentum as a 1500 kg truck traveling at 90 km/h?
31. ## physics

find the change n momentum of a 1120-kg car that increases its speed / what minimum force is need to do this?
32. ## Physics

A skydiver has a terminal velocity of 9.0 m/s. If they have a mass of 98, what is their k value for their air resistance? Use g = 10 m/s/s and do not report units on your answer, they should be N s/m.
33. ## physics

WHAT IS THE REASON BEHIND THE JISKHA"S TEACHERS TO BE NOTHING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!(except Writeacher and STEVE) ARE THEY DAFT OR NUISANCE!!!!!!!!!!!!!!!!!! ANSWWER Me QUICKLY !!!!!!!!!!!!!
34. ## physics

Describe how the energy from a rotating flywheel can be transferred to moving parts of a child's toy.
35. ## Physics

A spring has a a constant of 650 N/m. How far must it be compressed to push a 4kg object on a friction-less surface to 3 m/s?
36. ## physics

If your boat weighs 1400 N, how much water will it displace when it’s floating motionless at the surface of a lake?
37. ## physics

How high will an object rise if it is projected upward at a 45 degree angle and an initial velocity of 50 m/s?
38. ## science physics

i don't get how to solve this please help me Two resistors, 47 Ù and 82 Ù, are connected in series across a 45 V battery. What is the current in the circuit?
39. ## Physics

From the position vs time graph of an object moving with constant acceleration, how could you find the velocity
40. ## Physics

An elevator is moving upward at 0.97 m/s when it experiences an acceleration 0.34 m/s 2 downward, over a distance of 0.80 m. What will its final velocity be?
41. ## physics

how many revolutions per minute would a 15 m ferris wheel need to make for passengers to feel weightless at the top?
42. ## physics

Find the total force necessary to give a rocket of mass 25,000 slugs an acceleration of 28.0 ft/s2.
43. ## Physics

How long does it take T-Rex to reach its food 200m away assuming that he starts from rest and accelerates at 4.00 m/s2?

What voltage is necessary to produce a current of 200 amperes through a resistance of 1 x 10^-3 ohms?

What is the current produced by a 9-volt battery flowing through a resistance of 2 x 10^-4 ohms?
46. ## Physics

A motor cyclist travelling at 12m/s decelerate at 3m/s(squared)? How far does he travel while coming to rest?
47. ## physics

if a worker pushes a box 3 times as far as you do and exerts double the force you applied, which one of you does more work and by how much?
48. ## math or physics

Find the distance from 0 to 3 of the ∫ l3t-5ldt. I don't understand how the answer is 41/6.
49. ## physics

What is the magnitude and direction of an electric field that exerts a 4.00 ✕ 10 -5 N upward force on a - 1.80 µC charge? N/C
50. ## physics

A body immersed in liquid has an upthrust of 140N with a density of 12kg calculate the velocity
51. ## Physics

A loud speaker emits energy in all directions at a rate of 2.75 J/s . What is the intensity level at a distance of 25 m?
52. ## Physics

A train whose speed is 100km/hr rounds a curve whose radius of curvature is 150m what is the acceleration?
53. ## Health Physics

As one exhales, what change in energy takes place between the diaphragm and the air in the lungs?
54. ## Physics

A 200kg motorcycle is driving in a circular path at 1 rev per 5 seconds and the circle has r=12m
55. ## physics

How fast (in ) must a centrifuge rotate if a particle 8.00 from the axis of rotation is to experience an acceleration of 117000 's?
56. ## Physics

A solid weigh 45N and 15N respectively in air and water. Calculate the relative density
57. ## physics

Find the voltage increase when 12 J of work is done to push a 0.0013 C charge into an electric field.
58. ## physics

What is the number of the highest harmonic that could be heard by a person who is capable of hearing frequencies up to 1.00×104 ?
59. ## Physics

What will a spring scale read for the weight of a 75 kg woman in an elevator that moves upward with acceleration 0.30 g? w=?
60. ## Physics

What is the efficiency of a crane that used current of 8A at 150V to raise 450kg load at the rate of every minutes?
61. ## physics

A.Use newtons first law to explain why whiplash occurs? B.why are cars fitted with head rests?
62. ## physics

A 1.00 x 10^3 kg sports car accelerates from rest to 25.0 m/s in 7.50 s. What is the average power output of the automobile engine?
63. ## Physics

Calculate the length of a displaced pendulum Bob which pass through its lowest point twice every second. Take g=10m/s²
64. ## physics

A 8.2 kg object undergoes an acceleration of 2.5 m/s2. What is the magnitude of the resultant force acting on it? Answer in units of N
65. ## Physics

the speed of a train increases from 15 mi/h in a distance of 500 ft. calculate the average acceleration in ft/s squared
66. ## physics

Consider the motion of the tip of the minute hand of a clock. In one hour, the displacement and average velocity is .......
67. ## Another physics question...

Deduce the electric field strenght at a point midway between charges of 7.2*10^-6 C and -3.4*10^-6 C that are 2.0m apart from air. Thank you!
68. ## physics

How long will it take a 1030 W motor to lift a 330 kg piano to a sixth-story window 13.0 m above?
69. ## physics

Correct the following statement: The racing car rounds the turn at a constant velocity of 145 km/hr.
70. ## physics

what is the distance traveled by a vehicle in 12 minutes, if it's speed is 35km/h? And the answer I got was 7km but I got it wrong. Please help!
71. ## Physics

A positive and a negative charge, each of magnitude 1.0 10-5 C, are separated by a distance of 12 cm. Find the force on each of the particles
72. ## physics

A radio station is broadcasting at 90.7 mhz. compute for its wavelength in angstrom and energy in kilojoules.
73. ## Physics

what is the mass of hydrogen peroixide, H2O2, in 350 grams ofa 20% by weight solution?
74. ## physics

If you do 110 J of work to elevate a bucket of water, how much energy did you add to the gravitational field?
75. ## physics

Calculate the speed of sound wave in air if its frequencies and wavelengths are 256Hz and 1.32m
76. ## physics

A positive and a negative charge, each with a magnitude of 1.41 x 10^-5 C, are separated by a distance of 0.44 m. Find the force on each of the particles.
77. ## physics

A 1.56kg seagull dives through the air and gains 4495 of energy.What is the birds speed?
78. ## Physics

How much force is needed to bring a 3200 lb car from rest to a velocity of 44 ft/s in 8 seconds? Please indicate the formula used.
79. ## Physics

a child twirls a yo-yo about in a horizontal circle. The yo-yo has a mass of 0.20 kg and is attached to a string 0.8 m long. what is the velocity of the yo-yo? thanks!
80. ## physics

How much centripetal force is needed to keep a 0.20 kg ball on a 1.50 m string moving in a circular path with a speed of 3.0 m/s?
81. ## physics

Forces of 4.57 N and 4.74 N act at right angles on a reddish-green block of mass 5.76 kg. How much acceleration occurs?
82. ## physics

How much centripetal force is needed to keep a 0.20 kg ball on a 1.50 m string moving in a circular path with a speed of 3.0 m/s?
83. ## physics

How long will it take a 1280 W motor to lift a 345 kg piano to a sixth-story window 19.0 m above?
84. ## Physics

A 1300 kg sports car accelerates from rest to 85 km/h in 6.2 s. What is the average power delivered by the engine?
85. ## physics

An object is projected at an angle of elevation of 45 degree with a velocity of 100 m/s calculate its range
86. ## physics

A 0.49 cm high object is placed 8.5 cm in front of a diverging lens whose focal length is -7.5 cm. What is the height of the image?
87. ## physics

If you cover your home thermostat with a blanket, will it make the house hotter or colder, or have some other effect?
88. ## physics

at highway speeds, a particular automobile is capable of an acceleration of about 2.6 m/s^2. at this rate, how long does it take to accelerate from 60 km/h to 110 km/h?
89. ## Physics

an athlete executing a long jump leaving the ground at an angle of 30° and travels 8.9m .what was the take off speed?
90. ## physics

a car of mass(m)800kg initially at rest is accelerated at rate of 4m/s calculate the k.e @ 5seconds
91. ## Physics

Is this true or false? All objects moving in a circle are accelerated. I really don't uderstand this question.
92. ## PHYSICS

The force applied by the e-brake is F(eb) = m*a(eb) = -8.13*1452 = -12,100 N I didn't get the same answer - I got 11,804.76....please check
93. ## Physics

In general, what conditions with observable effects make magnets interact with non-magnet materials?
94. ## Physics

Calculate the distance (in km)that Larry runs if he maintains an average speed of 8km/hr for 45 minutes.

What happens when a conductor is wired in parallel with the bulb? Is the swich open or closed?
96. ## PHYSICS

A pebble is tossed off a skyscraper and reaches the groung 7.65 seconds later. How tall is this building? 7.65 s x 9.8 m/s^2 = 74.97 meters????? Not sure if I did this right? Thanks
97. ## Physics

Two spherical objects with a mass of 7.60 kg each are placed at a distance of 2.93 m apart. How many electrons need to leave each object so that the net force between them becomes zero?
98. ## physics

Explain how an object can orbit a planet & why astronauts float around in the orbiting space shuttle
99. ## Physics

Why is the total distance traveled by a mass traveling in a circle of radius R during n revolutions, 2piRn?
100. ## physics

What frequency would you need to produce a sound wave in room-temperature air with a wavelength of 9 m? the answer in Hz