74,641 results, page 70

1. ### physics

the substance which allows heat radiations to pass through is.a)iron b)water vapour c)wood d)dry air
2. ### physics

A violin string vibrates at 298 Hz when unfingered. At what frequency will it vibrate if it is fingered one sixth of the way down from the end?
3. ### physics

Calculate the half-life of a radioactive substance that decays by a factor of 3 in concentration every 1 million years
4. ### PHYSICS

A cell phone emits signs in approximately 750 Mhz. Which is the wavelength and energy of this radiation
5. ### physics

true of false- if you only want a small volume of hot water, you should place the immersion heater near the bottom?
6. ### physics

What minimum speed does a 150 g puck need to make it to the top of a 5.90 m-long, 21.0 degree frictionless ramp?
7. ### Physics

What is the force needed to start a 100 kg block sliding on a horizontal if the coefficients for static and kinetic are 0.75 and 0.5
8. ### physics

if you are stuck in the middle of a frictionless frozen lake with only your backpack, how can you get back safely to solid ground?
9. ### physics

if you are stuck in the middle of a frictionless frozen lake with only your backpack, how can you get back safely to solid ground?
10. ### physics

The distance between the midpoints of two metal balls,P and Q,respectively of masses 55 kg and 70 kg,is 80 cm (a)calculate the gravitational force that P exerts on Q thanks in advance
11. ### physics

An object with a height of 12cm is placed 4cm in front of a concave mirror whose radius of curvature is 16cm.
12. ### physics calc based

In the product F = qB (vectors), take q = 2 (neglecting the units of charge, q) and v = 2.0 i + 4.0 j + 6.0 k and F = 4.0 i + (-20 j) + 12 k . What then is B in unit-vector notation if Bx=By ?
13. ### physics

power applied to a particle varies with times as p=3t^2-2t+1 Watt where t is in second. And the change in its kinetic energy b/w time t=2s t=4s
14. ### Physics

How much time would Simpson save by in- creasing his average velocity to 65.8 km/h to the east? Answer in units of min
15. ### Physics

Describe the path of a moving body whose acceleration is constant in magnitude at all times and is perpendicular to the velocity.
16. ### Physics

Find the component form of ⃗v given a magni- tude of 9 and an angle of θ = 90◦ with positive
17. ### physics

A square conducting slab with 7 m sides carries a net charge of 89 mu or micro CC. what is the electric field?
18. ### Physics

What equation illustrates the relationship between the electric field strength and the potential difference? E = d / v E = v / d d = E(v) E = v(d) I'm honestly clueless on this one
19. ### physics

a stone of mass 50g is released from rest, Calculate it's kinetic energy after 6s from the beginning of the motion
20. ### physics

for an RLC circuit with a resistance of 11 k*ohm, a capacitance of 2 uF, and an inductance of 24 H, what frequency is needed to minimize the impedance?
21. ### Physics

As a block of wood with the mass of 2.00 kg slides along a floor, it's speed decreases from 4.0 m/s to 1.0 m/s. How much kinetic energy does it lose?
22. ### Physics

How many calories are absorbed by a copper spoon with a mass of 200 grams as it changes from 28°C to 33°C? A) 0.00027 B) 3 C) 90 D) 13,000 And this one. How do i solve this one?
23. ### Physics

Assuming that your lungs can function when under a pressure of 11 kPa, what is the deepest you could be under water and still breathe through a tube to the surface?
24. ### Physics

Bob (200kg) and Sally (40kg) want to make a see saw that will balance when they are both on 8it. If the board they have is 5m long, where should the fulcrum be placed?
25. ### physics

the current to an LC circuit is being supplied according to the function I(t)=2*sin(7t). what is the smallest value of t for which the inductor and capacitor each contain half of the energy?
26. ### physics

if you are stuck in the middle of a frictionless frozen lake with only your backpack, how can you get back safely to solid ground?
27. ### Physics

If a pair of carbon atoms were fused, and the product were to emit a beta particle, what element would be produced?
28. ### Physics

A body is thrown up with a velocity of 78.4m/s.find how height will with rise and how much time if it take to return its point of rejection?
29. ### physics

a race car's velocity increases from 4 m/s time interval, its average acceleration would be 10 m/s2 ? true or false ?
30. ### Physics

The distance between Earth and the Moon is 3.84 * 108 m. Show that the round-trip time for the light is 2.56 s Thanks in advance
31. ### physics

Calculate the speed at the edge of a disc of radius 4 cm that rotates at the rate of 8 rev/s. Answer in units of m/s.
32. ### Physics

What is the pressure at a depth of 80 m in the ocean? The density of seawater is 1. 03 × 10 3kg/m3. Please express your answer in units of atm.
33. ### Physics

What is the pressure at a depth of 80 m in the ocean? The density of seawater is 1. 03 × 10 3kg/m3. Please express your answer in units of atm.
34. ### physics

two forces of the same magnitude act at a point.the square of their resultant is 3 times the product of their magnitudes.the angle between them is?
35. ### physics help

how much work must be done to raise a 5kg block of steel from the ground to a height of 2m (in Joules) in the absence of friction?
36. ### physics

A large boulder is ejected vertically upward from a volcano with an initial speed of 41.0 . Air resistance may be ignored.
37. ### St. Basil's school. Physics

The time period of two pendulums are 1.44s and 0.36s respectively. Calculate the ratio of their lengths.
38. ### physics

A bus accelerates at 1.4 m/s2 from rest for 14 s. It then travels at constant speed for 23 s, after which it slows to a stop with an acceleration of magnitude 1.3 m/s2.
39. ### physics

A projectile is fired straight up at a speed of 15 m/s. How long does it take to reach the top of its motion? The acceleration of gravity is 9.8 m/s2 .
40. ### physics

I need to make a holder for a raw egg out of straws so when it is dropped from 8 feet. it will not break I need design ideas.
41. ### AP Physics

Two locomotives approach each other on parallel tracks. Each has a speed of v = 85 km/h with respect to the ground. If they are initially d = 7.0 km apart, how long will it be before they reach each other?
42. ### physics

A projectile is fired straight up at a speed of 15 m/s. How long does it take to reach the top of its motion? The acceleration of gravity is 9.8 m/s2 .
43. ### physics

Charge polarization is normally produced by: nuclear interactions. contact. induction. friction. electrostatic means.
44. ### Physics

Given a free falling object that is initially at rest, what are the objects displacement, velocity, and acceleration after 9 seconds?
45. ### Physics Help!

Find the total kinetic energy content of 1.55 moles of an ideal gas at temperature 435 K
46. ### Physics

if the body describes a vertical circle then the minimum velocity at angle theta from lowest position is
47. ### physics

A spring with a force constant of 100 N/m is used to push a 0.27 kg block of wood against a wall, as shown in the figure.
48. ### physics

a 70.o kg student runs up a 5.00 meter high stairway in a time of 5 seconds. how many watts of power did she develop?
49. ### Physics

An automobile is traveling 65mph. Its brakes decelerates at 6.0mps. How long will it takes to stop the car?
50. ### physics

A kangaroo jumps straight up to a vertical height of 1.19m, how long was it in the air before returning on earth
51. ### Quantum Physics

What is the probability current density of a particle with wavefunction ψ(x,t)=exp(iℏ(px−Et))?
52. ### physics

A 50 kg diver leaps off the 20 meter diving board with a velocity of 5 m/s. What is his kinetic energy just before hitting the water?
53. ### Physics

The established value for the speed of light in a vacuum is 299 792 458 m/s. What is the order-of-magnitude of this number?
54. ### Physics Help

What is the energy stored in the inductor shown in the figure after the switch has been closed for a very long time? Take V = 15 V, R = 600 §Ù and L = 10 mH.
55. ### PHYSICS

A 3.1 kg bundle starts up a 30° incline with 139 J of kinetic energy. How far will it slide up the plane if the coefficient of friction is 0.30?
56. ### PHYSICS

'show that a 2.5m length of wire with cross section area 0f 1.0mm and resistance of 0.75ohms has a resistivity o f 3.0 ×10-7'
57. ### physics

Calculate the energy released in the fusion reaction 2 3 4 1 1 H + 1 H->2 H +0 n. The atomic mass of 3 1 H (tritium is 3.016049 u. I am lost! help please!
58. ### physics

the time a male bungee jumps is freely falling is 1.5 seconds. what is the velocity of the jumper at the end
59. ### physics

a race car's velocity increases from 4 m/s to 36 m/s over a 4s time interval, its average acceleration would be 10 m/s2 true or false ?
60. ### Physics

The length of wire is 25.5cm and it's radius is 1.02mm. Calculate the percentage error in mesurement of its volume
61. ### general physics

If wind blows at 30 m/s over a house, what is the net force on the roof if its area is 300 m^2 and is flat?
62. ### physics

Calculate the magnitude of the electrostatic force the two down quarks inside a neutron exert on each other if they are separated by a distance of 0.71 fm.
63. ### physics

What is the magnitude of force required to accelerate a car of mass 1.7 Ã— 10Â³ kilograms by 4.75 meters/secondÃ†?
64. ### physics

a vertical object placed on a bench is observed to have three shadows of different sharpness,in different directions.explain tha observation
65. ### Physics

A car accelerates at a constant rate from 13m/s to 25m/s in 6.0seconds. What was its acceleration? How far did it travel in this time?
66. ### Physics

A car accelerates at a constant rate from 13m/s to 25m/s in 6.0seconds. What was its acceleration? How far did it travel in this time?
67. ### physics

How large a force (in newtons) is needed to accelerate a 3 metric-ton vehicle from rest to a speed of 50 km/hr in 4 s?
68. ### physics

An object experiences an impulse, moves and attains a momentum of 100 kg·m/sec. If its mass is 50 kg, what would its velocity be?
69. ### physics

Three blocks are suspended at rest by the system of strings and frictionless pulleys shown in the figure below, where W = 29.0 . What are the weights w1 and w2?
70. ### physics

an object undergoes an acceleration of 10m/s2 starting from rest. find the distance travelled by it in seconds
71. ### physics

Calculate the net charge on a substance consisting of a combination of 8.9 × 10 13 protons and 4.4 × 10 13 electrons. Answer in units of C
72. ### physics

A teacher is shot out of a cannon. He leaves the barrel at an angle of 25.0o to the ground with a velocity of 45.0 m/s. How far down range will he land?
73. ### Physics

If the visible part of an ice berg is 50mx50m in area and 20m is above the surface, what is the height, h? I tried using FB=FG but I don't get anywhere. Can anyone help me out?
74. ### Physics

A period pulse travel a distance at 20m in 1•00sec,if it's frequency is 2•0×10.calculate the wave length
75. ### physics

Calculate the speed of a satellite moving in a stable circular orbit about the Earth at a height of 5400km.
76. ### physics

A lamp operates with a current of 0.625A and a potential difference of 120V. What is the currnt flowing through the microwave?
77. ### Physics

According to special relativity, at high speeds the distance between distant locations is: a) shortened b) no different than if you were at rest c) lengthened
78. ### Physics

A bolt requires tightening to a torque of 98 N-m. If a wrench is 28 cm long, what perpendicular force should be applied at its end?
79. ### physics

A 67.5 kg hoop rolls along a horizontal floor so that its center of mass has a speed of 0.090 m/s. How much work must be done to stop it?
80. ### Physics

Find the number of revolutions of a bicycle wheel of diameter 0.7m when the bike goes a distance of 22m down the street.
81. ### physics

if a bus traverses a distance of 10,000 cm with the uniform velocity of 10 m/sec, what is its total time of travel?
82. ### Physics

Can scientists from other countries change what physicists in the United States think? Need help ASAP work due tomorrow XD
83. ### Physics

What is the shortes possible time in which a bacterium could travel a distance of 8.4 cm across a Petri dish at a constant speed of 3.5mm/s?
84. ### Physics

What minimum speed does a 100 g puck need to make it to the top of a 5.9 m-long, 29 degree frictionless ramp?
85. ### PHYSICS

What's the total mechanical energy of a 300kg satellite in circular orbit 1400km above Earth's surface?
86. ### Physics

What is the acceleration of a skateboard down a ramp inclined at 19.5 degrees to the horizontal? 3.271 is the answer. This shouldn't be too tough, but I can't get it. Thanks!
87. ### physics

a particle moving on a circlehas a velocity of m/s and normal acceleration of 10m/s2.determine the radius of the circle.
88. ### physics

okay a race car's velocity increases from 4 m/s to 36 m/s over a 4 s time innterval, its average acceleration would be 10 m/s 2 ? would this question be true ?
89. ### physics

an airplane flying at 150 km/hr encouters a headwind of 30 km/hr. draw a vector diagram of this including the resultant.
90. ### physics

A projectile is fired in such a way that its horizontal range is equal to 8.5 times its maximum height. What is the angle of projection?
91. ### college physics

A delivery truck travels 10 km north, 18 km east, and 29 km south. What is its final displacement (in km) from the origin?
92. ### Physics

Calculate the height through which a crane can lift a load of 4t , when its motor of 4HP operates for 10s. [Take g=10N/kg ]
93. ### grade 9 physics

A runner jogs 12km North then turns and runs 16km East three hours
94. ### Physics

An observer on Earth sees you travel 1000 m at half the speed of light. What distance do you think that you travelled?
95. ### physics

a particuler moves along the sides AB,BC,CD of a square of side 25m with a speed of 15m/s. Its average velocity is?
96. ### Physics

A loudspeaker emits energy equally in all directions at the rate of 1.75J/s. What is the intensity level at a distance of 15 m?
97. ### physics

compute the acceleration of a 1500-N block sliding down a 30 degrees incline. Assume friction is negligible
98. ### Physics

a 10-kg bos slides down a frictionless ramp with acceleration 3.6 m/s calculate the weight....the angle and normal force
99. ### Physics

a 10-kg bos slides down a frictionless ramp with acceleration 3.6 m/s calculate the weight....the angle and normal force
100. ### Physics

a 10-kg bos slides down a frictionless ramp with acceleration 3.6 m/s calculate the weight....the angle and normal force