# Thank you. I don't know if this one is right- At the speed of 2.5m/s, how many seconnds will it take the kayak to run a 4,500 m course? what is the speed of the kayak in kilometers per hour?

53,133 results
1. ## physics

A cart starts from position 4 (which is 20m above ground) in the figure below with a velocity of 11 m/s to the left. Find the speed with which the cart reaches positions 1, 2, and 3. Neglect friction. speed at position 1 m/s? speed at position 2 m/s? speed

2. ## Physics

1. While riding on an elevator descending with a constant speed of 1.5 m/s, you accidentally drop a book form under your arm. (a) How long does it take for the book to reach the elevator floor, 1.2 m below your arm? (b) What is your book's speed relative

3. ## Calculus

A man 2m tall walks away from a lamppost whose light is 5m above the ground. If he walks at a speed of 1.5m/s, at what rate is his shadow growing when he is 10m from the lamppost? I tried to draw a diagram, but I don't understand where the 5m is, the

4. ## physics - energy question

A simple pendulum, 2.0 m in length, is released with a push when the support string is at an angle of 25° from the vertical. If the initial speed of the suspended mass is 1.2 m/s when at the release point, what is its speed at the bottom of the swing? (g

5. ## Physics

A sky diver of mass 80.0 ks jumps from a slow-moving aircraft and reaches a terminal speed of 50.0 m/s. a) What is the acceleration of the sky diver when her speed is 30.0 m/s? What is the drag force on the diver when her speed is b) 50.0 m/s? c) 30.0 m/s?

6. ## Chemistry

The speed limit on a certain highway is 72km/h. What is the speed in cm/s? Could you go through each step on how to get the answer? Lots of the questions are like this one, but I don't know how to do them.

7. ## physics

A ventilation fan has blades 0.25 m in radius rotating at 20rpm. What is the tangential speed of each blade tip? i don't understand how to do tangential speed.

8. ## physics

2. a 755N diver drops from a board 10.0 m above the water's surface. Find the divers speed 5.00 m above the water's surface. then find the diver's speed just before striking the water. 3. if the diver in item 2 leaves the board with an initial upward speed

9. ## AP Physics - Work and Energy

A projectile is fired at an upward angle of 45 degrees from the top of a 265-m cliff with a speed of 185 m/s. What will be its speed when strikes the ground below? (Use conservation of energy.) I have a diagram of it but I don't know what equations to use.

10. ## Physics

A cart of mass M1 = 4.00 kg and initial speed = 4.00 m/s collides head on with a second cart of mass M2 = 2.00 kg at rest. Assuming that the collision is elastic, find the speed of M2 after the collision. i keep getting the wrong answer please help me.I

11. ## physics!-concervation of energy equations

2. a 755N diver drops from a board 10.0 m above the water's surface. Find the divers speed 5.00 m above the water's surface. then find the diver's speed just before striking the water. 3. if the diver in item 2 leaves the board with an initial upward speed

12. ## physics

You jog at 6.2 mi/h for 5.0 mi, then you jump into a car and drive for another 5.0 mi. With what average speed must you drive if your average speed for the entire 10.0 miles is to be 10.6 mi/h? I don't get why the answer isn't 15.

13. ## science/math

If a car can go from 0 to 60mi/hr in 8.0 seconds, what would be its final speed after 5.0 seconds if its starting speed were 50mi/hr? don't know what equation to use. please help

14. ## Physics Problems

I have a few questions that I don't understand and are having troulbe with, could you please help me out? Thanxs! What is the acceleration of a car that maintains a constant velocity of 100 km/hr for 10 seconds? (For this one don't I have to get the same

15. ## Physics

A motorcycle rider plans to make a jump off a ramp. If he leaves the ramp with a speed of 38.0m/s and has a speed of 36.3m/s at the top of his trajectory, determine his max height above the end of the ramp. Ignore friction and air resistance. i got 6.45m

16. ## Chemistry

a) Which is the greater speed, that of a bullet fired from a high powered M-16 rifle (2180 mi/hr) or the root mean square speed of H2 molecules at 25 degrees Celsius. I completed part a) however I don't know how to answer part b) b) At what temperature are

17. ## Physics

I must show my work for full credit. I need help on this question. I don't need answers, but could you help me figure it out. Thanks A microbiologist measures the speed of a swimming bacterium. The bacterium covers a distance of 2.16 microns in 5.0

18. ## Chemistry

What is the wavelength in nanometers of a photon with a frequency of 6.10 ✕ 10^14 sec-1? (The speed of light in a vacuum is 2.998 ✕ 108 m/s. Planck's constant is 6.626 ✕ 10^-34 J·s.) I know that speed of light = wavelength * velocity, but I don't

19. ## physics

At the Indianapolis 500, you can measure the speed of cars just by listening to the difference in pitch of the engine noise between approaching and receding cars. Suppose the sound of a certain car drops by a factor of 2.40 as it goes by on the

20. ## Physics

Tarzan swings on a 27.0 m long vine initially inclined at an angle of 33.0° with the vertical. (a) What is his speed at the bottom of the swing if he starts from rest? (b) What is his speed at the bottom of the swing if he pushes off with a speed of 3.00

21. ## physics

A golfer hits a ball from the origin with an initial speed of 35 m/s at an angle of 44 degrees above the horizontal axis. The ball is moving down when it lands on a green that is 3.00 m above the level where it was struck. Neglect air resistance. 1. How

22. ## Calculus - another question

"Margaret has found that by a proper choice of gears she can steadily increase her speed on her bike. One day she sets out and, ten minutes later, she achieves her cruising speed of 30km/h by increasing her speed steadily. How far did she travel in that

23. ## Science

A supersonic jet flying at 145 m/s is accelerated uniformly at the rate of 23.1 m/s squared for 20.0 s. a. What is its final velocity? b. The speed of sound in air is 331 m/s. How many times the speed of sound is the plane's final speed? I don't care what

the function f(x)= -o.005t^2+0.8t+12 models the relationship between a certain vehicle’s speed and fuel economy, where is the fuel economy in kilometres per litre and x is the speed of the vehicle in kilometres per hour. Determine the rate of change in

25. ## Calculus (urgent!!)

A particle moves with its position given by x=cos(2t) and y=sin(t), where positions are given in feet from the origin and time t is in seconds. A)Find the speed of the particle. Speed = ____________ (include units) B)Find the first positive time when the

26. ## Math

1) A car is traveling at a rate of 70 miles per hour. what is this speed in feet per minute. 2) Nina can braid 28 inches of rope in 1 hour. What is her speed in feet per hour? I am studying but I don't understand these questions. I have test tomorrow.

27. ## Physics

I understand that I have to use newtons laws of motion but I don't really get how to aplly them to this problem. Please help. An aircraft with a mass of 11000kg moving at constant speed and altitude is powered by propellers and experiences drag from air.

28. ## Science

The question in the book says: A wave has a wavelength of 2mm and a frequency of 3 Hz. At what speed does the wave travel? I know the answer is 6, because the formula is Speed= Wavelength X Frequency, but I don't know how to write the final answer, it's

29. ## Physics

A golfer hits a ball from the origin with an initial speed of 35 m/s at an angle of 44 degrees above the horizontal axis. The ball is moving down when it lands on a green that is 3.00 m above the level where it was struck. Neglect air resistance. 1. How

30. ## algebra 2

I don't know how to do this the speed of train A is 18mph slower than the speed of train B train A travels 190 miles in the same time it takes train B to travel 280 miles find the speed of each train please help so i can pass my quiz.

31. ## physics

Snowballs are thrown with a speed of 12.5 m/s from a roof 7.8 m above the ground. Snowball A is thrown straight downward; snowball B is thrown in a direction 16° above the horizontal. (a) Is the landing speed of snowball A greater than, less than, or the

32. ## Physics(check)

11)A race car travels on a racetrack at 38 m/s and slows at a constant rate to a velocity of 20 m/s over 10 s. How far does it move during this time? I don't know 12)The speed of a body is the distance traveled per unit time. Which of the following would

33. ## AP Physics Word Problems ASAP!

Could you please help me out with the following problems please? If a rocket initially at rest accelerates at a rate of 50 m/s^2 for one minute, its speed will be ? ( I know there are 60 seconds in 1 minute, so would I just use the formula, d=vt, and I

34. ## Math

An airplane flying into a headwind travels the 2800 mile flying distance between two cities in 4 hours and 40 minutes. On the return flight, the same distance is traveled in 4 hours. Find the air speed of the plane and the speed of the wind assuming that

35. ## Physics

A force of 165 N is needed to keep a small boat moving at 2.57 m/s. What is the power required to keep the boat moving at the steady speed? >> I understand that P=Fv but I don't understand the second question. If the resistive force of the water increases

36. ## Math

My question is about guess my rule, in Russian math. x - y 1=21 2=22 7=27 8= don't know 9= don't know _ = 33 33- don't know _ = 65 102=don't know _ - 130 and then it says Rule: y=... and so yeah. the signs that are like this _ mean I don't know basically.

37. ## physics

a bullet with a mass of 5 g and a speed of 600 m/s penetrates a tree to a depth of 4 cm. Assume that a constant frictional force stops the bullet. Calculate the magnitude of this frictional force. I used KE = 1/2 mv^2 = 900 J then F (friction ) = W/d =

38. ## physics

1)As a sound source moves away from a stationary observer, the number of waves will. A)increase B)decrease C)remain the same D)need to know the speed of the source (answer:decrease.) As the detector recedes from the source, the relative velocity is

On the surface of a planet an object is thrown vertically upward with an initial speed of 60 m/s. use a conservation of energy approach to determine the object's speed when the object is at a quarter of it's maximum height. (assume the planet has no

40. ## Physics (Momentum)

Can anyone please help me with this question? I don't understand why the speed is v m/s. A sport utility vehicle is travelling at a speed of v m/s. If its momentum has a magnitude of 32,800 kg·m/s, what is the SUV's mass? Thanks I know that I have to use

41. ## Physics

Can anyone please help me with this question? I don't understand why the speed is v m/s. A sport utility vehicle is travelling at a speed of v m/s. If its momentum has a magnitude of 32,800 kg·m/s, what is the SUV's mass? Thanks I know that I have to use

42. ## Science

An automobile accelerates 1.24 m/s^2 over 6.00 s to reach freeway speed at the end of an entrance ramp. If the cars final speed is 86.0 km/h, what was its initial speed when it began accelerating? Express your answer in km/h I can do it but I just don't

43. ## English

Talk with your partner about what you don't have to do during the vacation. What don't you have to do on vacation? 1. I don't have to go to school. 2. I don't have to take the bus. 3. I don't have to take bus number 5 to go to school. 4. I don't have to

44. ## Pre-Calculus

Each second after shut-off, the speed of the blade is 2/3 of the speed in the previous second. After the first 8 s, the saw has turned 258 times. What was the speed of the saw before the motor shut off, to the nearest tenth of a turn per second? I get

45. ## science

Thank you. I don't know if this one is right- At the speed of 2.5m/s, how many seconnds will it take the kayak to run a 4,500 m course? what is the speed of the kayak in kilometers per hour? speed= 4,500km/2.5h*60min/1 h =270,000/2.5=108,000km/h Thank you

46. ## Chemistry

Using Heisenberg's Principle, calculate for the following positions. a) a 1.54-mg mosquito moving at a speed of 1.82 m/s if the speed is known to within ± 0.01 m/s b) a proton moving at a speed of (4.67 ± 0.02) 104 m/s When I solved (a) I got 1.88e-30

47. ## Exploring Space

this is one questio which I'm stumped on. = y must we be able to travel at the speed of light to explore space. I don't realy know how to explain myself clearly and put that into an answer. I don't get this

48. ## Phyics Word Problems

Could you please check my work and help me with two of the problems. An airplane that flies at 100 km/h with a 10 km/h tailwind travels at 110 km/h relative to the ground. If it instead flies into a 10 km/h headwind, its groundspeed is 100km/h-10km/h = 90

49. ## Physics - drwls can you help me with this?

A 2.00kg block hangs from a rubber cord, being supported so that the cord is not stretched. The unstretched length of the cord is 0.500m and it's mass is 5.00g.The "spring constant" for the cord is 100N/m. Block is released and stops at lowest point. a)

50. ## physics

a car is travelling along a cruve having radius of curvature of 80.0 m, banked at an angle of theta=30. The coeff of static friction of ice is 0.05. What is: a) the slowest speed the car can negotiate the banked curve with? b) what is the fastest speed?

51. ## science

Okay, Ms. Sue. I got this and I don't think that it is right. this is the question - I wrote the answer at the bottom. I don't think that its right. speed=4,500km/2.5h*60min/1 h=270,000/2.5=108,000km/h I think that i'm confused. Thanks

52. ## Physics (ASAP)

Please I need help. I don't know how to do this problem without the SPEED VALUE. A sport utility vehicle is travelling at a speed of v m/s. If its momentum has a magnitude of 32,800 kg·m/s, what is the SUV's mass? _______ kg Thank you.

53. ## Physics

The best sprinters can run a 100 m in 10.0 s. A 77.2 kg sprinter accelerates uniformly for the first 51.0 m to reach top speed, which he maintains for the remaining 49.0 m. What is the average horizontal component of force exerted on his feet by the ground

54. ## English

I'm worried about my looks. 1. Why don't you put on cosmetics on your face? 2.Why don't you eat sereals and brown rice? 3. Why don't you do a plastic surgery? 4. Why don't you make double eyelids? 5. Why don't you have a double eyelid surgery? 6. Why don't

55. ## math

by how many order of magnitute is the speed of light greater than the average speed of grey sound? Rose Diamond when he set the hight gate track 710 m record of for this 47.43 sec in April 2003 710m/47.43s = close to 15 m/s. The speed of light is 3 x 10^8

56. ## science

The speed of light in a prticular ype of glass is 1.68x10^8 m/s. What is the index of refraction of the glass? I don't understand if how to solve this problem. Do you put an index of refraction of glass that you know or are you solveing for glass that you

57. ## Science

when you ride in a train that passes a train moving in the opposite direction, the other train appears to rush past you at a greater speed than if you were watching from a parked car at a crossing. how does the speed of your train affect your impression of

58. ## Physics

Car A and B are passing each other in different lanes. Car A has an initial speed of 15m/s and is gaining speed at 1.5m/s^2. Car B has an initial speed of 20m/s and is gaining speed at 2.0m/s^2. Find when and where the cars will pass one another and their

59. ## English

Talk about the things you don't have to do on Sunday. I don't have to study hard. I don't have to see teachers at school. I don't have to see my homeroom teacher. I don't have to walk to school. I don't have to clean my classroom. I don't have to mop the

60. ## physics

ok so I really don't get 2d collisions and I thought I knew how to do this one but I have no idea: A 104 kg baseball player jumps up verticlly to catch a baseball of mass .254 kg traveling horizontally with a speed of 28.6 m/s. If the vertical speed of the

61. ## physics

ok so I really don't get 2d collisions and I thought I knew how to do this one but I have no idea: A 104 kg baseball player jumps up verticlly to catch a baseball of mass .254 kg traveling horizontally with a speed of 28.6 m/s. If the vertical speed of the

62. ## trig

A barge is pulled by two tugboats. The first tugboat is traveling at a speed of 12 knots with heading 140°, and the second tugboat is traveling at a speed of 17 knots with heading 200°. Find the resulting speed and direction of the barge. (Round your

63. ## Physics

A car (mass 880 kg) is traveling with a speed of 44 mi/h. A bug (mass 7.9 mg) is traveling in the opposite direction. What speed would the bug need in order to slow down the truck by one mile per hour in a big bug splash (i.e., final speed 43 mi/h)? I

64. ## Physics

A golfer rides in a golf cart at an average speed of 3.10 m/s for 21.0 s. She then gets out of the cart and starts walking at an average speed of 1.60 m/s. For how long (in seconds) must she walk if her average speed for the entire trip, riding and

65. ## Physics

A golfer rides in a golf cart at an average speed of 3.93 m/s for 43.3 s. She then gets out of the cart and starts walking at an average speed of 1.13 m/s. For how long (in seconds) must she walk if her average speed for the entire trip, riding and

66. ## English

I¡¯m worried about my grandmother. 1. Why don¡¯t you visit her often and talk with her? 2. Why don¡¯t you take her to hospital? 3. Why don¡¯t you take care of her? 4. Why don¡¯t you ask your parents to bring her to your apartment? 5. Why don¡¯t

67. ## math

Running at a constant speed, Andrea covers 15 miles in 2.5 hrs. At this speed, how many minutes will it take her to run 2 miles? I know that I need to use conversion but i don't know how to convert it.

A kayaker paddled 2 hours with a 6 mph current in a river. The return trip against the same current took 3 hours. Find the speed the kayaker would make in still water. The speed is 6 mph slower going upstream and 6 mph faster going downstream. Distance

69. ## physics

a rock is thrown at a downwards angle of 15 degrees from the top of a 120 m cliff with a speed of 25 m/s. what will be its speed when it strokes the ground at the base of the cliff? I know to use the conservation of energy but I don't know how to set it

70. ## Physics

a speed boat is moving though the water at a speed of 28 m/s when the engine stalls. the boat comes to a halt over 120m, what is the time it takes to stop and what is the acceleration. im trying to figure it out but i don't know what kinematic equation to

71. ## College Physics

A car (mass 880 kg) is traveling with a speed of 44 mi/h. A bug (mass 7.9 mg) is traveling in the opposite direction. What speed would the bug need in order to slow down the truck by one mile per hour in a big bug splash (i.e., final speed 43 mi/h)?.

72. ## english

In the following paragraph, are the words I have in capital letters adverbs? A five-speed bike combines the WORST of a three-speed and ten-speed. The typical five-speed is built on the same heavy frame as the three-speed, OFTEN, has the five-speed gear

73. ## Physics

Two main strategies are employed to deflect an asteroid: destruction or slowing it down by at least 425 s so that the earth can move out of the impact zone. Assume perfect inelastic collision. (a) If we know the speed of the asteroid (va), mass (ma), and

74. ## Maths

Any help with the following would be greatly appreciated. I don't understand how to use the information given to create the equation. 1) A car travels between A and B at an average speed of 60 km/h. If the car increased its average speed to 100 km/h it

75. ## AP Physics

A racing car travels on a circular track of radius 220 m, moving with a constant linear speed of 48.9 m/s. Find its angular speed. Answer in units of rads/s. I already mutiplied 2π x 220. But I don't know what to do from there? Any help please? Thanks!

76. ## physics--HELP

a giant robot tosses a ball up, from a height of 80 meters, with an initial velocity of Vo = 60 m/s, use 10 m/s^2 as the acceleration due to gravity. what will be the minimum velocity of the ball and when and where will that occur? [i don't know how you

77. ## Physics

If I take a glob of mud and throw it against a wall with the speed of V and stops in time T and than I take a ball and throw it and it hits the wall with speed V and leaves the wall a time T later at a speed of 0.5V and they both have same value and mass,

78. ## Dr. Bob can you look at this

If I take a glob of mud and throw it against a wall with the speed of V and stops in time T and than I take a ball and throw it and it hits the wall with speed V and leaves the wall a time T later at a speed of 0.5V and they both have same value and mass,

79. ## physics

This question is also frustrating me. I just don't a single clue how to do it. A pilot must fly his plane north with a speed of 550 km/hr. A wind of 138 km/hr is blowing at an angle of 31 degrees N of E . What speed does the plane need to keep the desired

80. ## AP Physics

Could you please help me out with the following problems please? If a rocket initially at rest accelerates at a rate of 50 m/s^2 for one minute, its speed will be ? ( I know there are 60 seconds in 1 minute, so would I just use the formula, d=vt, and I

81. ## English

1. Don't pull my leg. 2. Don't tease me. 3. Don't kid me. 4. Don't play a trick on me. 5. Don't play tricks/jokes/pranks on me. 6. Don't play a joke on me. 7. Don't play a prank on me. -------------------------- Are they all the same in meaning? From #4 to

82. ## physics

A friend in a spaceship travels past you at a high speed. He tells you that his ship is 20m long and that the identical ship you are sitting in is 19m long. According to your observations, (a) how long is your ship?? (B) how long is his ship?? (c) what is

83. ## physics

i figured out the ratio its 1.10 , don't know how to get the second part please help!! my understanding is not good enough to answer part 2 Pretend you have two containers, one filled with ethyl alcohol and the other filled with benzene. How would you show

84. ## chemistry

Is average speed (u) the same as root mean square velocity? I found a formula for root mean square velocity which I know is also used for average speed: (3RT/MM)^1/2 Is that right? I don't know what that is supposed to be an average OF, but is all

85. ## physics

A ball is dropped into a well. A splash is heard 43 seconds later. The speed of sound (the speed at which sound travels through the air) is 345 m/s. HOW DEEP WAS THE WELL? I don't even know which equation to plug this into. At first I just tried s=d/t->

86. ## College Physics

In Chapter 3 we learned that the force of air drag on an object moving rapidly through the air is proportional to v2, where v is the speed of the ball relative to the air. The same relation applies to the force of the wind on the blades of a wind turbine

87. ## Physics

A force of 165 N is needed to keep a small boat moving at 2.57 m/s. What is the power required to keep the boat moving at the steady speed? >> I understand that P=Fv but I don't understand the second question. If the resistive force of the water increases

88. ## Physics

If I take a glob of mud and throw it against a wall with the speed of V and stops in time T and than I take a ball and throw it and it hits the wall with speed V and leaves the wall a time T later at a speed of 0.5V and they both have same value and mass,

89. ## physics

In a game of pool the cue ball strikes another ball of the same mass and initially at rest. After the collision the cue ball moves at 3.50 m/s along a line making an angle of 22 degrees with its original direction of motion. and the second ball had a speed

90. ## Physics

Help I don't understand how to do this homework question, we didn't go over any like it in class. A car has an average speed of 80.0km/h for 1 hour, then an average speed of 90.0km/h for 2 hours during a 3 hour trip. what was the average speed for the 3

91. ## physics

1)As a sound source moves away from a stationary observer, the number of waves will. decrease 2)How fast should a car move toward you for the car's horn to sound 2.88% higher in frequency than when the car is stationary? The speed of sound is 343 m/s.

92. ## Physics

A 145. drop tower. This is an evacuated vertical tower through which , among other possibilities, a 1m diameter sphere containing an experimental package can be dropped. a) How long is the sphere in free fall? b)What is its speed just as it reached a

93. ## Physics

A person walks first at a constant speed of 4.70 m/s along a straight line from point A to point B and then back along the line from B to A at a constant speed of 2.80 m/s. (a) What is her average speed over the entire trip? (b) What is her average

94. ## physics problems

please check my answers. 17. explain how the sport of pole vaulting dramatically changed when flexible fiberglass poles replaced still wodden poles? -the fiberglass poles had more momentum and PE than still wooden poles? 20. does the international space

95. ## Physics Probelms ASAP

Could you please check my work and help me with a couple. An airplane that flies at 100 km/h with a 10 km/h tailwind travels at 110 km/h relative to the ground. If it instead flies into a 10 km/h headwind, its groundspeed is : 110 km/h /2= 55 km/h The

96. ## physics

An elastic collision occurs between two air hockey pucks in which one puck is at rest and the other is moving with a speed of 0.7 m/s. After the collision, the puck initially in motion makes an angle of 20.00 o with its original direction, and the struck

97. ## English

I¡¯m worried about my height. 1. Why don¡¯t you buy a jump rope and jump rope from time to time? 2. Why don¡¯t you play basketball with others in the gym? 3. Why don¡¯t you do gymnastics on a regular basis? 4. Why don¡¯t you do yoga at home? 5.

98. ## Geometry

Hey. I was wondering if someone could help me with this question? I asked my teacher to explain it to me, but I still don't get it. I don't care for an answer, I just want to know how to solve. Thanks in advance. - A (-3, -4) - B (5, 2) - C (11, -6) What

99. ## English

1. Don't make a noise at the movies. 2. Don't talk out loud at the movie. 3. Don't talk to others in the movies. 4. Don't talk aloud in the movie. 5. Don't have a conversation loudly in the movie theater. 6. Don't disturb others in the cinema. 7. Don't

100. ## physics (urgent)

A car of mass 1000kg is travelling along a straight flat road at a constant speed of 30.0ms^-1. It then accelerates with constant acceleration of 3.00ms^-2 for 10.0s, after which it continues to travels at a constant speed. Determine: (a) The final speed