# Physics!

74,459 results, page 83

1. ### physics

A 55.0-kg skydiver free falls for a period of time before opening his parachute. What is his kinetic energy when he reaches a velocity of 16.0 meters/second?
2. ### physics

A 55.0-kg skydiver free falls for a period of time before opening his parachute. What is his kinetic energy when he reaches a velocity of 16.0 meters/second?
3. ### physics

A Corvette, initially traveling at a speed of 6 m/s, speeds up (accelerates) at a rate of 0.2 m/s2 for 3 s. How far does it travel during that time? I tried d=vi*t-.2*t^2 but I did not get the correct answer
4. ### Physics

Find the average velocity over the time interval from 1 to 3 seconds. Express your answer in meters per second to the nearest integer.
5. ### physics

A large merry-go-round completes one revolution every 10.5 s. Compute the acceleration of a child seated on it, a distance of 5.20 m from its center. what is the magnitude?
6. ### physics

what sould be the angular speed with which the earth have to rotate on its axis so that a person on the equator would weight 3/5th as much as present..??
7. ### Physics with Calc

A point charge of 1.8uC (microcoulumbs) is at the center of a Gaussian cube 55 cm on edge. What is the net electric flux through the surface?
8. ### Physics

A Jet has a liftoff speed of 160 km/hr. What minimum uniform acceleration does this require if the aircraft is to be airborne after a takeoff run of 300m?
9. ### physics

Two stars, a binary star system, with a mass of m1 = 5.88E29 and m2 = 2.27E30 kg are separated by a distance of 2.55E11 m. What is the gravitational force between them?
10. ### physics

how does mass energy relate to the hydrogen bomb? i can't find anything that simply explains this to me and i need6 it for a powerpoint presentation tomorrow please help.
11. ### Physics

an airplane travels due north at 500km/hr there's a cross wind of 100km/hr determine the displacement of the air craft after 1 hour
12. ### physics

Two small metal spheres with masses 2.0 and 4.0 are tied together by a 5.4--long massless string and are at rest on a frictionless surface. Each is charged to +2.4 .
13. ### physics

7.If a washing machine's drum has a radius of 28 cm and spins at 4.1 rev/s, what is the strength of the artificial gravity to which the clothes are subjected? Express your answer as a multiple of g.
14. ### Physics

Two objects attract each other gravitionally with a force of 2.5 *10^-10 N when they are .25m apart. Their total mass is 4.0kg. Find their individual masses.
15. ### physics

If a washing machine's drum has a radius of 24 cm and spins at 4.1 rev/s, what is the strength of the artificial gravity to which the clothes are subjected? Express your answer as a multiple of g.
16. ### physics

How long would a 150 W lightbulb have to glow to produce the same amount of energy expended by Georgie? Answer in units of s.
17. ### physics

Question part Points Submissions 1 2 0/1 0/1 0/10 0/10 Total 0/2 A 3.5-kg block slides with a speed of 1.6 m/s on a frictionless, horizontal surface until it encounters a spring.
18. ### physics

A loaded truck can accelerate at 6.4 m/s^2. It loses its load so that it is only 0.9 as massive. By what factor must the acceleration change for the same driving force?
19. ### physics

A loaded truck can accelerate at 6.4 m/s^2. It loses its load so that it is only 0.9 as massive. By what factor must the acceleration change for the same driving force?
20. ### physics

A skydiver jumps out of a plane. Does the mechanical energy of the jumper change while she is falling? Ignore the effects of air resistance.
21. ### Physics

The constant torque required to accelerate a disk (of rotational inertia I) from rest to a speed of f rotations per second in a time interval of t is:
22. ### physics

Explain how you can tell the following statement is false A neutron was moving in a circle while speeding up. As a result, gamma rays were emitted.
23. ### physics

Explain how you can tell the following statement is false A neutron was moving in a circle while speeding up. As a result, gamma rays were emitted.
24. ### physics

an thelet completes one round of circular track of diameter 200m in 40 secomds. wht will be the distance covered t the end of 2min & 20 s.
25. ### physics

electricity is measured in kilowatts-hours, kW*h. this quantity can be converted to which other unit that measures energy? a.Pascals b.Joules c.Newtons d. Watts
26. ### physics

How much force is the air exerting on the front surface of the book with dimensions 19 x 27 cm. Assume atmospheric pressure equal to 100,000 Pa.
27. ### physics

If a burning log is a black object with a surface area of 0.35 m2 and a temperature of 800 ˚C, how much power does it emit as thermal radiation?
28. ### Physics

A 120-V rms voltage at 1000 Hz is applied to a resistor and an inductor in series. If the impedance of this circuit is 110 Ù, what is the maximum value of the current?
29. ### Physics

Suppose that you want to take a photograph of yourself as you look at your image in a flat mirror 1.6 away. For what distance should the camera lens be focused?
30. ### physics

How much power is used by a 50Kg athlete in climbing a 10m high ladder in 9.8 sec? 1000 J 2000 J 3000 J 4000 J
31. ### Physics

German silver wire has a cross-sectional area of 2.047 x 10^-3 cm^2. How many meters are needed to make a resistance of 100 (omega)? I don't know where to begin.
32. ### physics

which of the following properties of a sound wave determines its pitch: wavelength, speed, amplitude, or frequency? Plese show work, Thank you, Silly
33. ### Physics

A Saturn V rocket with an Apollo spacecraft attached has a combined mass of 2.1 105 kg and will reach a speed of 11.2 km/s. How much kinetic energy will it then have?
34. ### Physics

With an average acceleration of −2.2 m/s^2, how long will it take a cyclist to bring a bicycle with an initial speed of 14.5 m/s to a complete stop? Answer in units of s.

36. ### physics

the 3 lb block A rests on a surface for which the coefficient of kinetic is Mk=.30 determine the distance the 8-lb cylinder B must descend so that A has a speed of Va = 5ft/s starting from rest.
37. ### science(physics)

the sum of three forces f1=100n, f2=80n, f3=60n acting on a particle is zero. The angle between f1 and f2 is: Please solve
38. ### physics

As a baseball is being caught, its speed goes from 30 to 0 m/s in about 0.005 its mass is 0.145. A) What is the baseballs acceleration in m/s^2 and in g's? B) What is the size of force acting on it?
39. ### physics

how the frequency of the sound produced will change in the case of aluminium sting of length 15cm when the string is tied between two ends
40. ### physics

A 1000 Kgs Vehicle moving with a sppeed of 20 meter per sec. is brought to rest in a distance of 50 metres. find the acceleration
41. ### Physics

Hi, Which correctly expresses the relationship between wavelength (L), speed (V) and perios (T) of a sinusodial wavform ? a) L = T/V b) L= 2fxV/ T c) L= 1 / V x T D) L= V/T e) L = V x T f) L= V x T/ 2f I feel it is option (d) ..please check for me .. and thanx
42. ### physics

Find the magnitude and direction of the net electrostatic force exerted on the point charge q3 in the figure below, where q = +2.5 μC and d = 28 cm. The picture is of a square. q1=+q, q2=-2q, q3=-3q, q4=-4
43. ### physics

Find the magnitude and direction of the net electrostatic force exerted on the point charge q3 in the figure below, where q = +2.5 μC and d = 28 cm. The picture is of a square. q1=+q, q2=-2q, q3=-3q, q4=-4
44. ### Physics

How much work is done to move a 1400 kg car from rest to 25 m/s.If this takes place over a distance of 130 m, what is the average net force?
45. ### Physics

Measurements can be described as accurate and/or precise. Define accuracy and precision and give examples of how those terms could be used to describe a measurement.
46. ### science/physics

I was in a crosswalk, struck by a truck weighing 3,400 lbs. (traveling at about 8 K/hr) - what was the force per square inch exerted on me?
47. ### Physics

An austronaut orbits the Earth in the space shuttle, in one complete orbit, is the magnitude of thr displacement the same as the distance traveled?
48. ### Physics

Simpson drives his car with an average velocity of 45.1 km/h to the east. How long will it take him to drive 153 km on a straight highway? Answer in units of h
49. ### physics

Find the electric flux through each surface. (Use any variable or symbol stated above along with the following as necessary: ε0.)
50. ### physics

a car accelerates uniformly from rest to a speed of 21.8 km/h in 5.9 seconds.find the distance it travels during this time. answer in units of meters
51. ### physics

How far should and object be from a concave sperical mirror of radius 36cm to form a real image one-ninth it's size?
52. ### physics

a trench mortar fires a shell at an angle of 30 degrees with the horizontal and with a speed of 500 m/s. find its range and the maximum height it attains?
53. ### physics

Charge of uniform surface density (0.2 nC/m2) is distributed over the entire xy plane. Determine the magnitude of the electric field at any point having z = 2 m.
54. ### physics

Describe briefly how the volume of a given mass of water changes when it is cooled from 7 ^0 C to 1^0 C use the terms increase, decrease and maximum or minimum
55. ### physics

Describe briefly how the volume of a given mass of water changes when it is cooled from 7 ^0 C to 1^0 C use the terms increase, decrease and maximum or minimum
56. ### physics

Two particles with Q1 = 40 µC and Q2 = 87 µC are initially separated by a distance of 2.6 m and then brought closer together so that the final separation is 1.7 m. What is the change in the electric potential energy?
57. ### physics

If you drop an object, it will accelerate down- ward at a rate of g = 9.8 m/s2. If you throw it downward instead, its accel- eration (in the absence of air resistance) will be
58. ### physics

Add the following vectors 1.50m{North 45 degrees West}, 10m{South30degreesEast}, 25Meters[South60mWest] pls help. explain to me how to solve it
59. ### Physics

at what distance would a convex magnifing lens that has a focal length of 10 cm have to be held for an image to appear upright and 3 cm tall? [6.67cm]
60. ### physics

A 1.0kg ball initially at rest rolls down a plane at 35 degrees. Find the net force. pls i really need help
61. ### physics

When the play button is pressed, a CD accelerates uniformly from rest to 495 rev/min in 3.1 revolutions. If the CD has a radius of 6 cm, and a mass of 17 g, what is the torque exerted on it?
62. ### physics

A load of mass 80kg fell dwn from d floor of a lorry whch is 1.2m high.calculate wrk dne by gravity on d land
63. ### Physics

Which electromagnetic radiation can be used in space to detect low temperatures? Gamma Rays Infra Red Ultra Violet Or any of the others?
64. ### physics

A rotating uniform cylindrical platform of mass 240 kg and radius 5.7 m slows down from 3.9 rev/s to rest in 16 s when the driving motor is disconnected.
65. ### physics

many vacuum flasks have steel walls instead of glass. how would this effect how gfast some hot coffee cools
66. ### physics

many vacuum flasks have steel walls instead of glass. how would this effect how fast some hot coffee cools?
67. ### physics

A ball of mass moves in a horizontal circular path of radius a with speed v as shown in the illustration below. Find the tension in the cord.
68. ### Physics/Science

At what point in the swing of a pendulum is the maximum amount of the ball's motion transferred to the object it hits? What does this "kinetic energy" depend on?
69. ### physics (biomechanics)

briefly explain how an athlete competing in the long jump can prevent the trunk from pitching forward after take-off
70. ### Physics

Your swimming pool is square and 6.1 m on a side. It is 1.4 m deep in the morning. If the temperature changes by 19°C during the afternoon, how much does the depth of the water increase?
71. ### physics

how do u find the horizontal force needed to push a wheel that weighs 300N and has a radius of 30m.it also lies on the stairs of 10m
72. ### Physics/Science

If a lever problem asks you to find a way to "lift" something, does that mean to balance the object(s), or to tilt it past the equilibrium?
73. ### physics

a toaster draws a current of 13.0A and has an electric potential difference of 120.V. For how long must it remain on to use 2.0x10^5J of electrical energy?
74. ### Physics

A 70.50 kg man rides a Ferris wheel with a radius of 10.3 m at a velocity of 5.00 m/s. What is the centripetal force that she experiences expressed with the correct number of significant figures?
75. ### Physics

You drive your car 2 km to the gas station, 4 km to the shopping mall to let your mother off, and 4.5 km back home. The trip takes 20 min. What is your velocity in m/s?
76. ### Physics

A drag racer starts her car from rest and accelerates at 9.0 m/s2for the entire distance of 60.0 m. What is its speed at the end of the run? Answer in units of m/s.
77. ### Physics

PLEASE HELP! and include steps of how you solved it! What magnitude of force, acting for 0.025 s, will change the velocity of a 100 g ball from 30 m/s eastward to 40 m/s westward?
78. ### physics

A young boy swings a yo-yo horizontally above his head so that the yo-yo has a cen- tripetal acceleration of 240 m/s2. If the yo-yo’s string is 0.29 m long, what is the yo-yo’s tangential speed
79. ### physics

What reaction would you get from francium and water in outer space and what if you added hydrogen to the experiment as far as being used for fuel for travel
80. ### Physics

What happens to the internal energy of an ideal gas when it is heated from 0C to 4C? a. increases b. decreases c. change in number of atoms d. increase in volume of substance
81. ### physics

What constant horizontal force, acting over 16 m of level trail, gives a friction-free 51-kg skier, starting from rest, a speed of 5.7 m/s?
82. ### physics

what is the magnitude of the centripetal force acting on the earth as it orbits the sun assuming a circular orbital speed of 3.00 X 10^4 meters per second
83. ### physics

a hairdryer turns 250J of electrical energy into 50J of heated air. how efficient is this machine and how much is wasted to sound?
84. ### physics

If two cars are moving head on toward each other at 88 km/h(55mi/h, and their drivers apply their brakes when they are 85 m apart, will they collide? This is a yes or no answer and explain why
85. ### physics science

Please can you help as I am stuck, Describe ib detail, how you would carry out an investigation to measure the density of a block of aluminium? Thankyou
86. ### physics science

Please can you help as I am stuck, Describe ib detail, how you would carry out an investigation to measure the density of a block of aluminium? Thankyou
87. ### physics

At high speeds, a particular automobile is capable of an acceleration of about 0.510 m/s^2. At this rate, how long (in seconds) does it take to accelerate from 95.0 km/hr to 101 km/hr?
88. ### Physics

A plane flies at 800km/h in stationary air. The distance to be traveled is 3000km. What was the wind speed if the journey actually takes 4.0 hours?
89. ### physics

A cannon is fired from a cliff 190 m high downward at an angle of 21° 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?
90. ### physics

A cannon is fired from a cliff 190 m high downward at an angle of 21° 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?
91. ### physics

If a violin string vibrates at 1720Hz, what is the wavelength of the sound produced in the surrounding air? (assume T=20 degree Celsius and speed is 344m/s)
92. ### Physics

A cannon is fired from a cliff 190 m high downward at an angle of 21° 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?
93. ### Physics

If the ball is tossed upward at 20 m/s, how long should it take before it reverses its direction (reaches its maximum height where its velocity is zero)?
94. ### Physics

Eighty calories must be added to one gram of ice at 0ºC to melt it. What is the approximate mechanical equivalent of this amount of energy?
95. ### Physics

A cannon is fired from a cliff 190 m high downward at an angle of 21° 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?
96. ### physics

n boat starts from rest and accelerates at a constant rate to a final speed of 28 m/s over a distance of 780 m. How much time will this take?
97. ### physics

A golf ball is struck with a five iron on level ground. It lands 92.7 m away 4.40 s later. What was (a) the direction and (b) the magnitude of the initial velocity?
98. ### Physics

A baseball is thrown vertically upward (assumed to be the positive direction) with a speed of 19.3 m/s from a height of 1.18 m. How high does the ball rise from its original position?
99. ### Physics

Three identical charges of 2.0 uC are placed at the vertices of an equilateral triangle, 0.15m on a side. Find the net force acting on each angle.
100. ### physics

a ball is thrown from level ground at 24 m/s, 30 degree above horizontal. How much time will it take to reach its maximum height? solution