Physics!

74,459 results, page 87

1. Physics

When a solar flare erupts on the surface of the sun, how many minutes after it occurs does its light show up in an astronomer's telescope on earth? I am totally confused..help!
2. physics

1.2g projectil e shot horiz. at a speed of 105m/s off a 124m high cliff. a) determine time taken by the projectile to return to the ground..
3. physics

A stone is thrown downward into a well with an initial speed of 5.00 m/s. The sound of splash is heard 1.50 s later. Find the depth of the well if the air temperature is 15.0 ˚C?
4. physics

A stone is rotated steadily in a horizantal circle with a period T by a string of length L. If the tension in the stringis constant and L increases by 1% find the percentage change in T.
5. Physics

A rocket blasts off with acceleration of 5 m/s squared. After 1 min it runs out of fuel. What is the max height and total time in the air?
6. Physics

display.cgi?id=1225682948 I'm still confused about how you got the (1/8)kx^2 and how to find the weight's maximum height at the top of its path through the air.
7. Physics

Can someone help me with finding out the magnitude of the gravitational force a person with a mass of 67.5 kg would experience while standing on the surface of Earth? Thanx in advance.
8. Urgent Physics!

A top starting from rest is spun for 3 seconds achieving an angular speed of 20 rad/s. How many radians has it gone through in this time? (a is constant)
9. physics

During a workout, a person repeatedly lifts a 13 lb barbell through a distance of 1.5 ft. How many "reps" of this lift are required to burn off 100 Cal?
10. physics

Two freight cars, each with a mass of 2.5 multiplied by 10^5 kg, collide and stick together. One was initially moving at 3.4 m/s and the other was at rest. What is their final speed?
11. Physics or Science?

Why liquid soap dispensed through a small spout by pressing on it, solidifies interfering with its smooth ejection? thanks so much for an answer! Pietra
12. physics

race car travels on racetrack at 38m/s and slowa at a constant rate of 20m/s over 10s how far does it move during this time
13. Physics

Which of the following physical properties can be used to measure temperature using a thermometer? A. volume B. pressure C. density D. viscosity I think the correct answer is D?
14. physics

Two freight cars, each with a mass of 3.9 105 kg, collide and stick together. One was initially moving at 3.2 m/s and the other was at rest. What is their final speed in m/s?
15. PHYSICS

Estimate the terminal speed of a wooden sphere (density 0.700 g/cm3) falling through air if its radius is 3.20 cm and its drag coefficient is 0.470.
16. Physics

A projectile is launched at an angle of 6.0 degrees above the horizontal. Which component of the velocity vector remains the same during the flight (neglecting friction).
17. physics

A satellite orbits at an average altitude of h = 423 km. How long does it need to complete one full orbit? Use REarth = 6370 km and mEarth = 5.98 x 10^24 kg
18. physics

At what displacement from the equilibrium is the total energy of a simple harmonic oscillator one - sixths KE and five - sixth PE? Answer should be in terms of the amplitude A.
19. integrated physics and chemistry

classes of steel and iron are defined by the amount of WHAT? and other elements present in the alloy. is it zinc,tin,carbon,or aluminum?
20. physics

Suppose David Ortiz hits a home run which travels 361. feet (110. m). Assuming it left the bat at 50.°, how fast was it hit?
21. physics

how does the shotspotter system can determine the location of a shooting, given the initial muzzle report and the fact that this sound moves out in a spherical wavefront?
22. physics

if you wished to warm 100 kg of water by 15 degrees celsius for your bath, how much heat would be required? (give your answer in calories and joules)
23. Physics

Four 50-\mu {\rm{C}} charges are brought from far apart onto a line where they're spaced at 2.0-{\rm cm} intervals. How much work does it take to assemble this charge distribution?
24. Physics

How is it that an electron accelerates towards the protons (nucleus) in a hydrogen atom? I had thought that the electric forces acting on each other is equal so they are in equilibrium.
25. Physics

How is it that an electron accelerates towards the protons (nucleus) in a hydrogen atom? I had thought that the electric forces acting on each other is equal so they are in equilibrium.
26. physics

Two freight cars, each with a mass of 3.9 105 kg, collide and stick together. One was initially moving at 3.2 m/s and the other was at rest. What is their final speed in m/s?
27. physics

ok so dr= 2i + 3j while F= 5i + 2j It wants me to find the work. now i know w=Fxdr. what i want to know is why when you take the dot product of both, you get a different answer compared to when you just multiply the magnitudes.
28. physics

Determine how much water would be present in a 10 tonne sample of lignite, has a moisture content of 65%, before crushing and drying. 10 tonnes is 10,000 kg.
29. physics

A 22cm diameter bowling ball has a terminal speed of 77 m/s. What is the balls mass. I need to get the answer in kg. I can`t figure this one out for some reason. Thanks!!
30. physics

A thin 12 cm long solenoid has a total of 460 turns of wire and carries a current of 2.1 A. Calculate the magnitude of the field inside near the center.
31. physics help

A flywheel turns through 32 rev as it slows from an angular speed of 2.1 rad/s to a stop. How much time is required for it to complete the first 16 of the 32 revolutions?
32. Physics

An oscillator with a mass of 520 g and a period of1.2 s has an amplitude that decreases by 2.20% during each complete oscillation. At what time will the energy be reduced to 15.0% of its initial value?
33. Physics

The nucleus of the helium atom contains two protons that are separated by about 3.0 x 10-15 m. Find the magnitude of the electrostatic force that each proton exerts on the other
34. physics

In a right triangle ABC, C = 90°, a = 21 ft and b = 76 ft. Solve for all the missing parts using the given information. (Round each answer to the nearest whole number.)
35. Physics for Life science

1.Since action and reaction are exactly equal and oppositely directed, how is ever possible for a net force to be acting on the body?
36. physics for life sciences

since action and reaction are exactly equal and oppositely directed how is it ever possible for a net force to be acting on a body?
37. physics

A big yo-yo(radius .2m, mass 20kg) has a string wrapped about its circumference. If yo-yo falls, how far does it fall in 2 seconds? (The yo-yo is shaped like a disk)
38. physics

Two identical loudspeakers are 2 m apart. A person stands 4.6 m from one speaker and 3.4 m from the other. What is the lowest frequency at which destructive interference will occur at this point?
39. Physics

A simple pendulum, 2.0 m in length, is released from rest when the support string is at an angle of 25 from the vertical. What is the speed of the suspended mass at the bottom of the swing?
40. physics

(a) What linear speed must an Earth satellite have to be in a circular orbit at an altitude of 153 km? m/s (b) What is the period of revolution? min Read the eBook
41. physics

please differentiate between vibration, amplitude and frequency by giving relevant examples. I cant understand these concepts. I would be very grateful if they explained
42. physics

a mass of 0.1kg falls freely under the action of gravity .find the force acting on it its momentum kinetic energy after 10s?
43. Physics

Convert 341 m/s into km/h. (I have to leave the final answer to the correct number of digits according to the certainty rule for multiplying and dividing)
44. PHYSICS

The velocity of a diver just before hitting the water is -8.7 m/s, where the minus sign indicates that her motion is directly downward. What is her displacement during the last 0.89 s of the dive?
45. College Physics

A 3.0 kg black is at reat on a horizontal floor. If you push horizontally on the 3.0 kg block with a force of 12.0 N, it just starts to move. What is the coefficient of static friction?
46. Physics

A point (labelled P in the figure) is attached to the rim of a disk of radius 0.2 m, which can turn around an axis through its center. It is rotating counterclockwise with a speed of 2.5 m/s.
47. physics

A box is sliding down a ramp sloping 25° above the horizontal. The coefficient of kinetic friction is 0.15. What is the acceleration? The answer is 2.8 m/s^2. How can this be solved with out mass?
48. physics

A cannon is fired from a cliff 200 m high downward at an angle of 30o with respect to the horizontal. If the muzzle velocity is 34 m/s, what is its speed (in m/s) when it hits the ground?
49. physics

A cannon is fired from a cliff 200 m high downward at an angle of 30o with respect to the horizontal. If the muzzle velocity is 34 m/s, what is its speed (in m/s) when it hits the ground?
50. physics

A cannon is fired from a cliff 200 m high downward at an angle of 30o with respect to the horizontal. If the muzzle velocity is 34 m/s, what is its speed (in m/s) when it hits the ground?
51. physics

A cannon is fired from a cliff 200 m high downward at an angle of 30o with respect to the horizontal. If the muzzle velocity is 34 m/s, what is its speed (in m/s) when it hits the ground?
52. Physics

If a set of displacement vectors laid head to tail forms a closed polygon, the resultant is zero. Is this statement true? Explain your reasoning.
53. physics

What is the smallest radius of an unbanked (flat) track around which a bicyclist can travel if her speed is 31 km/h and the coefficient of static friction between the tires and the road is 0.29?
54. physics

An airplane whose airspeed is 295 km/h flies parallel to the direction of a wind with a speed of 40.0 km/h. What are the two possible speeds of the plane relative to the ground?
55. Physics 1

A rock is thrown straight upward with an initial velocity of 9.6 m/s in a location where the acceleration due to gravity has a magnitude of 9.81 m/s2. To what height does it rise? Help meh please.
56. physics

an anti aircraft shell is fired vertically upward with a muzzle velocity of 200 m/sec. Compute theinstantaneous velocities at the ends of 30 & 50 seconds.
57. Physics

A ball was thrown with a velocity of 150 ft/ s at angle of 45 degrees above the horizontal. a)Find the range and the time of flight. b)What is the maximum height reached?
58. physics

If a loaded truck that can accelerate at 1 m/s2 loses its load and has four-fifths of its original mass, what acceleration can it attain if the same driving force acts on it?
59. Physics

Suppose that you are standing on a train accelerating at 0.33g. What minimum coefficient of static friction must exist between your feet and the floor if you are not to slide?
60. Physics

Suppose that you are standing on a train accelerating at 0.33g. What minimum coefficient of static friction must exist between your feet and the floor if you are not to slide?
61. physics

If we apply 300 kJ of heat to 2500 moles of air at constant pressure, what is the change in internal energy? Answer a. 214 kJ. b. 100 kJ. c. 180 kJ. d. 75 kJ.
62. Physics

How much work did the movers do (horizontally) pushing a 140-kg crate 10.1 m across a rough floor without acceleration, if the effective coefficient of friction was 0.60?
63. Physics

How much work did the movers do (horizontally) pushing a 140-kg crate 10.1 m across a rough floor without acceleration, if the effective coefficient of friction was 0.60?
64. PHYSICS

How much work did the movers do (horizontally) pushing a 140-kg crate 10.1 m across a rough floor without acceleration, if the effective coefficient of friction was 0.60?
65. physics

How much work did the movers do (horizontally) pushing a 180- crate 10.6 across a rough floor without acceleration, if the effective coefficient of friction was 0.50?
66. Physics

A heavy freight train has a mass of 14000 metric tons. If the locomotive can pull with a force of 645000 N, how long does it take to increase it's speed from 0 to 69.8 km/h?
67. physics

A heavy freight train has a mass of 14000 metric tons. If the locomotive can pull with a force of 645000 N, how long does it take to increase it's speed from 0 to 69.8 km/h?
68. Physics

A heavy freight train has a mass of 14000 metric tons. If the locomotive can pull with a force of 645000 N, how long does it take to increase it's speed from 0 to 69.8 km/h?
69. Physics

A heavy freight train has a mass of 14000 metric tons. If the locomotive can pull with a force of 645000 N, how long does it take to increase it's speed from 0 to 69.8 km/h?
70. physics

A heavy freight train has a mass of 11800 metric tons. If the locomotive can pull with a force of 691000 N, how long does it take to increase it's speed from 0 to 70.3 km/h?
71. PHYSICS

A CAR IS BEING DRIVEN BY AFORCE OF 2.5*10POWER10N.TRAVELLING AT ACONSTANT SPEED OF 5m/s,IT TAKES 2 MINUTES TO REACH A CERTAIN PLACE.CALCULATE THE WORK DONE.
72. Physics

Using the definition of the scalar product, find the angles between the following pairs of vectors. A = - 4 i + 2 j + 2 k and B = - 3 j - 3 k I understand to do [(A).(B)]/|A|*|B| = cos theta; but I'm getting 0 for |A| and don't know how to access it from there.
73. Physics

A heavy freight train has a mass of 11800 metric tons. If the locomotive can pull with a force of 691000 N, how long does it take to increase it's speed from 0 to 70.3 km/h?
74. physics

A heavy freight train has a mass of 11800 metric tons. If the locomotive can pull with a force of 691000 N, how long does it take to increase it's speed from 0 to 70.3 km/h?
75. physics

A heavy freight train has a mass of 11800 metric tons. If the locomotive can pull with a force of 691000 N, how long does it take to increase it's speed from 0 to 70.3 km/h?
76. Physics

A skydiver has an air resistance force of 1193 N and a mass of 94 kg, what is her current acceleration? Take down to be POSITIVE and use g = 10 m/s/s. Please report your units as "m/s/s"
77. physics

in a racing competition a car is driving at 69km/h and the driver can complete 8 full circles in 6 mins. calculate the radius of the circular path in meters?
78. physics

A 7 kg block slides on a horizontal frictionless surface with a speed of 1.2 m/s. It is brought momentarily to rest when it hits a bumper that compresses a spring. The acceleration of gravity is 9.8 m/s^2.
79. Physics

A 0.2 kg object that stretches a spring 6.5 cm from its natural length when hanging at rest oscillates with an amplitude of 1.5 cm. The acceleration of gravity is 9.81 m/s2. Find the total energy of the system.
80. College Physics

An ambulance is approaching at 80 mph (35.8 m/s). If the siren produces a continuous 400 Hz tone, what frequency do you hear? Assume the speed of sound to be 340 m/s.
81. physics

A rocket moves upward, starting from rest with an acceleration of 28.8 m/s2 for 4.13 s. It runs out of fuel at the end of the 4.13 s but does not stop. How high does it rise above the ground?
82. Physics

A rocket moves upward, starting from rest with an acceleration of 35.0 m/s2 for 5.63 s. It runs out of fuel at the end of the 5.63 s but does not stop. How high does it rise above the ground?
83. Physics

A rocket moves upward, starting from rest with an acceleration of 35.0 m/s2 for 5.63 s. It runs out of fuel at the end of the 5.63 s but does not stop. How high does it rise above the ground?
84. Physics

A rocket moves upward, starting from rest with an acceleration of 35.0 m/s2 for 5.63 s. It runs out of fuel at the end of the 5.63 s but does not stop. How high does it rise above the ground?
85. Physics

A rocket moves upward, starting from rest with an acceleration of 35.0 m/s2 for 5.63 s. It runs out of fuel at the end of the 5.63 s but does not stop. How high does it rise above the ground?
86. physics

A hypothetical planet has a radius 2.1 times that of Earth, but has the same mass. What is the acceleration due to gravity near its surface? What equation should i use?
87. physics

A 95 N block rests on a table. The sus- pended mass has a weight of 22 N. What frictional force is required to keep the blocks from moving? Answer in units of N.
88. Physics

The velocity of a diver just before hitting the water is -8.7 m/s, where the minus sign indicates that her motion is directly downward. What is her displacement during the last 0.98 s of the dive?
89. physics

The velocity of a diver just before hitting the water is -8.8 m/s, where the minus sign indicates that her motion is directly downward. What is her displacement during the last 0.93 s of the dive?
90. physics

The velocity of a diver just before hitting the water is -8.8 m/s, where the minus sign indicates that her motion is directly downward. What is her displacement during the last 0.93 s of the dive?
91. physics

What force must be exerted to prevent a truck weighing 15 tons from rolling down an inclined plane which makes an angle of 3 degrees with the horizontal.
92. physics

The asteroid Ceres has a mass 7.061 × 1020 kg and a radius of 505.2 km. What is g on the surface? The value of the universal gravitational constant is 6.67259 × 10−11 N · m2/kg2.
93. Physics

How much work must be done to bring three electrons from a great distance apart to within 2.1Ã—10âˆ’10 {\rm m} from one another (at the corners of an equilateral triangle)?
94. physics

water 20 degrees celsius flows through a 25 mm diameter pipe at a rate of 50 liters per minute. is this laminar or turbulant flow or both?
95. physics

A car traveling along a level road uniformly increases its speed from rest to 28m/s in 8.0s. Show that it travels a distance of 112m in this time.
96. physics

In a distant planet, a freely falling object gains speed at a steady rate of 25 m/s during each 1.2 seconds of fall. The gravity acceleration there is: 122 m/s2 0.05 m/s2 30 m/s2 22 m/s2 5 m/s2 20.8 m/s2
97. physics

Find the horizontal distance the skier travels before coming to rest if the incline also has a coefficient of kinetic friction equal to 0.228
98. Physics

How do you solve this problem? How fast (in rpm) must a centrifuge rotate if a particle 9.00cm from the axis of rotation is to experience an acceleration of 115,000 g's?
99. physics

prepare a standard solution of oxalic acid with a concentration of 0.05mol.dm3. a report of the investigation. give the aim, apparatus, method and results.
100. Physics-10

A vehicle that weighs 400N on the surface of the earth is traveling in outer space at a speed of 400m/s. it can be stopped by applying a constant force of 20N for?