# An open railroad car of mass 2449 kg is coasting with an initial speed of 17 m/s on a frictionless, horizontal track. It is raining, and water begins to accumulate in the car. After some time, it is found that

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1. ### physics

An open railroad car of mass 2449 kg is coasting with an initial speed of 17 m/s on a frictionless, horizontal track. It is raining, and water begins to accumulate in the car. After some time, it is found that the speed of the car is only 10 m/s. How much water (in kilograms) ...
2. ### Physics

An open railroad car of mass 2445 kg is coasting with an initial speed of 22 m/s on a frictionless, horizontal track. It is raining, and water begins to accumulate in the car. After some time, it is found that the speed of the car is only 5 m/s. How much water (in kilograms) ...
3. ### Physics

A railroad car (m=3000 kg) is coasting along a level track with an initial speed of 22 m/s. A load of coal is then dropped into the car as sketched in the figure below. (a) What are the velocities of the car and the coal before the collision along the x direction? Vcar=____m/s...
4. ### Physics

A 3800 kg open railroad car coasts along with a constant speed of 8.60 m/s on a level track. Snow begins to fall vertically and fills the car at a rate of 3.50 kg/min. ignoring friction with the tracks what is the speed of the car after 90.0 minutes?
5. ### PHYSICS

A 5630 kg open railroad car coasts along with a constant speed of 8.64 m/s on a level track. Snow begins to fall vertically and fills the car at a rate of 3.50 kg per minute. Ignoring friction with the tracks, what is the speed of the car after 94.8 min?
6. ### Physics

An open train car moves with speed 11.3 m/s on a flat frictionless railroad track, with no engine pulling the car. It begins to rain. The rain falls straight down and begins to fill the train car. The speed of the car 1. increases. 2. decreases. 3. stays the same. A(n) 71.6 kg...
7. ### Physics

A 3600 kg open railroad car coasts along with a constant speed of 11.0 m/s on a level track. Snow begins to fall vertically and fills the car at a rate of 3.70 kg/min. Ignoring friction with the tracks, what is the speed of the car after 80.0 min?
8. ### College Physics

A 3400 kg open railroad car coasts along with a constant speed of 7.50 m/s on a level track. Snow begins to fall vertically and fills the car at a rate of 5.10 kg/min.Ignoring friction with the tracks, what is the speed of the car after 85.0 min ?
9. ### physicis

A freight car, open at the top, weighing 2.80 tons, is coasting along a level track with negligible friction at 4.10 ft/s when it begins to rain hard. The raindrops fall vertically with respect to the ground. What is the speed (in feet/second) of the car when it has collected ...
10. ### Physics

A 14000 kg railroad car travels alone on a level frictionless track with a constant speed of 24.0 m/s. A 6500 kg additional load is dropped onto the car. What then will be the car's speed?
11. ### physics

A 12100 kg railroad car travels alone on a level frictionless track with a constant speed of 20.5 m/s. A 5850 kg load, initially at rest, is dropped onto the car. What will be the car's new speed?
12. ### Physics

A 12100kg railroad car travels alone on a level frictionless track with a constant speed of 15.0m/s . A 6100kg load, initially at rest, is dropped onto the car. What is the car's new speed?
13. ### college physics

A 12100 kg railroad car travels alone on a level frictionless track with a constant speed of 20.5 m/s. A 5850 kg load, initially at rest, is dropped onto the car. What will be the car's new speed? Please help!
14. ### Physics

A 17000 kg railroad car travels along on a level frictionless track with a constant speed of 23.0 m/s. A 5100 kg additional load is dropped onto the car. What then will be its speed in meters/second?
15. ### Physics

A railroad car with a mass of 12400 kg collides and couples with a second car of mass 18700 kg that is initially at rest. The first car is moving with a speed of 7.7 m/s prior to the collision. (a) What is the initial momentum of the first car? (b) If external forces can be ...
16. ### physics

Four railroad cars, each of mass 2.50 x 104 kg, are coupled together and coasting along horizontal tracks at some speed vi. Superman, riding on the second car, uncouples the very front car and gives it a big push, increasing its speed in the same direction to 4.00 m/s. The ...
17. ### physics

A railroad car rolling along by itself is passing by a grain elevator, which is dumping grain into it at a constant rate. (a) Does momentum conservation imply that the railroad car should be slowing down as it passes the grain elevator? Assume that the track is frictionless ...
18. ### physics

An open train car, with a mass of 2070 kg, coasts along a horizontal track at the speed 2.31 m/s. The car passes under a loading chute and, as it does so, gravel falls vertically into it for 3.25 s at the rate of 491 kg/s. What is the car's speed after the loading is completed?
19. ### Physics

An open train car, with a mass of 2150 kg, coasts along a horizontal track at the speed 2.29 m/s. The car passes under a loading chute and, as it does so, gravel falls vertically into it for 2.67 s at the rate of 441 kg/s. What is the car's speed after the loading is completed...
20. ### Physics

A wooden boxcar is moving along a straight railroad track at speed v1. A sniper fires a bullet (initial speed v2) at it from a high-powered rifle. The bullet passes though both lengthwise walls of the car, its entrance and exit holes being exactly opposite each as viewed from ...
21. ### physics

A military gun is mounted on a railroad car (m = 1590 kg) as shown in Figure P7.34. There is no frictional force on the car, the track is horizontal, and the car is initially at rest. The gun then fires a shell of mass 26 kg with a velocity of 280 m/s at an angle of 28° with ...
22. ### Physics

A 200 toy car is placed on a narrow 64--diameter track with wheel grooves that keep the car going in a circle. The 1.5 track is free to turn on a frictionless, vertical axis. The spokes have negligible mass. After the car's switch is turned on, it soon reaches a steady speed ...
23. ### Physics

A rock is thrown into a railroad car standing on a level frictionless track. If the rock has a mass of ms = 1.100 kg and is tossed with a velocity v = 6.3 m/s, how far up will the car go (mc = 5.400 kg) before stopping? Please explain
24. ### Physics

A 245 g toy car is placed on a narrow 70-cm-diameter track with wheel grooves that keep the car going in a circle. The 1.0 kg track is free to turn on a frictionless, vertical axis. The spokes have negligible mass. After the car's switch is turned on, it soon reaches a steady ...
25. ### physics

A block of mass 0.570 kg is pushed against a horizontal spring of negligible mass until the spring is compressed a distance x. The force constant of the spring is 450 N/m. When it is released, the block travels along a frictionless, horizontal surface to point B, the bottom of...
26. ### Physics

A railroad car with a mass of 12000 kg collides and couples with a second car of mass 18000 kg that is initially at rest. The first car is moving with a speed of 9 m/s before collision. If external forces can be ignored, what is the final speed of the two railroad cars after ...

A rocket car is traveling on a linear horizontal frictionless track when it suddenly runs out of fuel. The car has achieved a speed of 100 meters per second at the very moment the fuel is completely spent. The track then suddenly changes to a 30-degree incline from the ...
28. ### science

A block of mass 0.5 kg is pushed a distance x against a spring with k=450 N/m. When released the block slides along a frictionless horizontal surface to a point B, the bottom of a vertical circular track of radius R=1 meter. The track is not smooth. When the block reaches ...
29. ### physics

A 100-g toy car is propelled by a compressed spring that starts it moving. The car follows the curved track Show that the final speed of the toy car is 0.687 m/s if its initial speed is 2.00 m/s and it coasts up the frictionless slope, gaining 0.180 m in altitude
30. ### Physics

A military gun is mounted on a railroad car (m = 1500 kg). There is no frictional force on the car, the track is horizontal, and the car is initially at rest. The gun then fires a shell of mass 30 kg with a velocity of 300 m/s at an angle of 40° with respect to the horizontal...
31. ### Psychics

A freight car is moving freely along a railroad track at 7.0 m/s and collides with a tanker car that is at rest. After the collision, the two cars stick together and continue to move down the track. What is the magnitude of the final velocity of the cars if the freight car has...
32. ### physics

A railroad car containing explosive material is initially traveling south at a speed of 4.5 m/s on level ground. The total mass of the car plus explosives is 2.9 104 kg. An accidental spark ignites the explosive, and the car breaks into two pieces, which then roll away along ...
33. ### Physics

An object moving along a horizontal track collides with and compresses a light spring (which obeys Hooke's Law) located at the end of the track. The spring constant is 38.6 N/m, the mass of the object 0.270 kg and the speed of the object is 1.20 m/s immediately before the ...
34. ### Physic

A block of mass 0.500 kg is pushed against a horizontal spring of negligible mass until the spring is compressed a distance x ( see Fig. below)The force constant ofthe spring is 450 N/rn. When it is released the block travels along a frictionless, horizontal surface to point B...
35. ### physics

A car moves with speed v on a horizontal circular track of radius R. The height of the car's center of mass is h, and the separation between the inner and outer wheels is d. The road is dry, and the car does not skid. Find the maximum speed the car can have without overturning.
36. ### Physics (Algebra-based)

A block starts at rest and slides down a frictionless track except for a small rough area on a horizontal section of the track.It leaves the track horizontally, flies through the air, and subsequently strikes the ground. gravity= 9.81 m/s^2. height1=4.1m---- is initially ...
37. ### physics (work/nonconservative forces)

An object moving along a horizontal track collides with and compresses a light spring (which obeys Hooke's Law) located at the end of the track. The spring constant is 47.3 N/m, the mass of the object 0.230 kg and the speed of the object is 1.80 m/s immediately before the ...
38. ### Physics

A cannon on a railroad car is facing in a direction parallel to the tracks. It fires a 99 kg shell at a speed of 105 m/s (relative to the ground) at an angle of 60.0° above the horizontal. If the cannon plus car have a mass of 5.5 104 kg, what is the recoil speed of the car ...
39. ### physics

A cannon on a railroad car is facing in a direction parallel to the tracks (the figure below ). It fires a 99-kg shell at a speed of 105 m/s (relative to the ground) at an angle of 60 above the horizontal. If the cannon plus car have a mass of 4.6 104 kg, what is the recoil ...
40. ### physics

alculate the final speed of a 1500 kg roller coaster if it has an initial speed of 16 m/s but reduces its elevation by 8.6 m by coasting down a frictionless incline.
41. ### Physics

Steel Phantom is a roller coaster in Pennsylvania that, like the Desperado in Nevada, has a vertical drop of 68.6m Suppose a roller-coaster car with a mass of 1000 kg travels from the top of that drop without friction. The car then decelerates along a horizontal stretch of ...
42. ### Physics

A car is doing a loop-the-loop. The loop has a radius of .4m. Assume the car is starting with the minimum speed it needs in order to stay in contact with the track at all times (at the top of the track, the car is not applying a force to the track). neglect friction. What is ...
43. ### PHYSICS

How do I solve this? A mine car (mass=380 kg) rolls at a speed of 0.50 m/s on a horizontal track, as the drawing shows. A 170-kg chunk of coal has a speed of 0.92 m/s when it leaves the chute (at a 25 degree incline). Determine the speed of the car–coal system after the coal...
44. ### physics

A 500g block is released from rest and slides down a frictionless track that begins 2m above the horizontal. At the bottom of the track, where the surface is horizontal, the block strikes and sticks to a light spring with a spring constant of 20.0N/m. Find the maximum distance...
45. ### physics

A railway flat car is rushing along a level frictionless track at a speed of 45m/s. Mounted on the car and aimed forward is a cannon that fires 65 kg cannon balls with a muzzle speed of 625m/s. The total mass of the car, the cannon, and the large supply of cannon balls on the ...
46. ### physics

A railway flat car is rushing along a level frictionless track at a speed of 45m/s. Mounted on the car and aimed forward is a cannon that fires 65 kg cannon balls with a muzzle speed of 625m/s. The total mass of the car, the cannon, and the large supply of cannon balls on the ...
47. ### physics help

1. A roller coaster car starts from rest and rolls down a frictionless track, reaching speed fv at the bottom. a. If you want the car to go two times as fast at the bottom, by what factor must you increase the height of the track? b. Does your answer to part (a) depend on ...
48. ### Physics

As shown in the figure below, cars #1 and #2 are sliding across a horizontal frictionless surface. The cars are equipped with a coupling arrangement similar to the one on railroad cars. Car #1 overtakes car #2 and they have a totally inelastic collision and become coupled ...
49. ### Physics

A 500 g block is released from rest and slides down a frictionless track that begins h = 1.70 m above the horizontal, as shown in Figure P13.56. At the bottom of the track, where the surface is horizontal, the block strikes and sticks to a light spring with a spring constant ...
50. ### physics

Starting with an initial speed v0, a mass m slides down a curved frictionless track (a shown in the figure below), arriving at the bottom with a speed v. From what vertical elevation h did it start?
51. ### Physics

A great white shark of mass m1, coasting through the water in a nearly frictionless way at speed v1 engulfs a tuna of mass m2=0.10 m1 traveling in the same direction at speed v2 swallowing it in one bite. a) What is the speed of the shark after its meal? b) Did the shark gain...
52. ### Physics

A roller-coaster car rolls down a track, reaching a speed of v0 at the bottom. If the height of the track is increased by a factor of 2.00, assuming the track is frictionless, by what factor will the speed at the bottom increase?
53. ### Physics

A mine car (mass 380 kg) rolls at a speed of 0.5 m/s on a horizontal track, as the drawing shows. A 150 kg chunk of coal has a speed of 0.80 m/s when it leaves the chute. Determine the velocity of the car/coal system after the coal has come to rest in the car.
54. ### physics

A ski jumper starts from rest 44.0 m above the ground on a frictionless track, and flies off the track at an angle of 45.0° above the horizontal and at a height of 14.0 m from the ground. Neglect air resistance. (a) What is his speed when he leaves the track? m/s (b) What is ...
55. ### physics

A mass M = 0.464 kg moves with an initial speed v = 2.98 m/s on a level frictionless air track. The mass is initially a distance D = 0.250 m away from a spring with k = 844 N/m, which is mounted rigidly at one end of the air track. The mass compresses the spring a maximum ...
56. ### physics

A mine car, whose mass is 590 kg, rolls at a speed of 0.5 m/s on a horizontal track, as the drawing shows. A 150 kg chunk of coal has a speed of 0.95 m/s when it leaves the chute. Determine the velocity of the car/coal system after the coal has come to rest in the car.
57. ### physics

2 identical cars capable of accelerating at 3.00m/s^2 are racing on a straight track with running starts. car A has an initial speed of 2.50m/s and car B has an initial speed of 5.00m/s. what is the seperation of the 2 cars after 10seconds? which car is moving faster after ...
58. ### physics

A mine car (mass = 452 kg) rolls at a speed of 0.356 m/s on a horizontal track, as the drawing shows. A 179-kg chunk of coal has a speed of 0.863 m/s when it leaves the chute. Determine the velocity of the car/coal system after the coal has come to rest in the car.
59. ### Physics

A railroad flatcar of weight W can roll without friction along astraight horizontal track. Initially, a man of weight w is standing on the car, which is moving to the right with speed v_0. What is the change in velocity of the car if the man runs to the left so that his speed ...
60. ### physics

A mine car, mass= 440 kg rolls at a speed of 0.50 m/s on a horizontal track. A 150-kg chunk of coal has a speed of 0.80 m/s when it leaves the chute. The chunk of coal falls into the car at a 25 degree angle. Determine the velocity of the car/coal system after the coal has ...
61. ### Physics

A ski jumper starts from rest 51.0 m above the ground on a frictionless track and flies off the track at an angle of 45.0° above the horizontal and at a height of 12.0 m above the ground. Neglect air resistance. (a) What is her speed when she leaves the track? (b) What is the...
62. ### Physics 141

A mine car (mass mcar = 444 kg) rolls at a speed of vcar = 0.52 m/s on a horizontal track, as the drawing shows. An mcoal = 141 kg chunk of coal has a speed of vcoal = 0.79 m/s when it leaves the chute. Determine the speed of the car-coal system after the coal has come to rest...
63. ### Physics

A block of mass m is given an initial speed of v along a horizontal frictional track. It travels a distance d and comes to a rest. the coefficient of kinetic friction between the block and the track is ....
64. ### physics

A 0.70 kg block along a horizontal track has a speed of 1.10 m/s immediately before colliding with a light spring of force constant 3.50 N/m located at the end of the track. (a) What is the spring’s maximum compression if the track is frictionless?
65. ### Physics

A 500 g block is released from rest and slides down a frictionless track that begins h = 1.70 m above the horizontal, as shown in Figure P13.56. At the bottom of the track, where the surface is horizontal, the block strikes and sticks to a light spring with a spring constant ...
66. ### physics

A 14.5 kg toy car is driving around a horizontal circular track with a period of 8.0 seconds. The radius of the circular track is 1.1 meters. What is the force of friction in Newtons between the car and the track that is necessary for the car to remain on the track?
67. ### physics

A 14.5 kg toy car is driving around a horizontal circular track with a period of 8.0 seconds. The radius of the circular track is 1.1 meters. What is the force of friction in Newtons between the car and the track that is necessary for the car to remain on the track?
68. ### physics

A 0.230-kg block along a horizontal track has a speed of 1.70 m/s immediately before colliding with a light spring of force constant 48.0 N/m located at the end of the track. What is the spring's maximum compression if the track is frictionless?
69. ### physics

A 0.290-kg block along a horizontal track has a speed of 1.30 m/s immediately before colliding with a light spring of force constant 53.4 N/m located at the end of the track. (a) What is the spring's maximum compression if the track is frictionless? m
70. ### physics

1. An object of mass m and initial speed v0 sliding on a horizontal frictionless surface encounters a frictionless ramp. To what vertical height will the object rise before coming to rest?
71. ### phyiscs

A 14.5 kg toy car is driving around a horizontal circular track with a period of 8.0 seconds. The radius of the circular track is 1.1 meters. What is the force of friction in Newtons between the car and the track that is necessary for the car to remain on the track? how do i ...
72. ### physics

A little red wagon with mass 8.00 moves in a straight line on a frictionless horizontal surface. It has an initial speed of 3.80 and then is pushed 4.7 in the direction of the initial velocity by a force with a magnitude of 10.0 .
73. ### physics

A railroad car of mass 2500 kg moving at 5.00 m/s collides and couples with two coupled railroad cars, each of the same mass as the single car and moving in the same direction at 2.20 m/s. (a) What is the speed of the three coupled cars after the collision?
74. ### physics

A railroad car with a mass of 2.35 × 104 kg moving at 3.90 m/s collides and joins with two railroad cars already joined together, each with the same mass as the single car and initially moving in the same direction at 1.25 m/s. a) What is the final speed of the three joined ...
75. ### Physics

A railroad car with a mass of 2.33 × 104 kg moving at 3.71 m/s collides and joins with two railroad cars already joined together, each with the same mass as the single car and initially moving in the same direction at 1.44 m/s.What is the final speed of the three joined cars ...
76. ### Physics 1

A cart with mass 340 g moving on a frictionless linear air track at an initial speed of 1.5 m/s undergoes an elastic collision with an initially stationary cart of unknown mass. After the collision, the first cart continues in its original direction at 0.42 m/s. (a) What is ...
77. ### Physics

A rollercoaster car speeds up and down a hill past points a, b, and c as shown. The car has a mass of 500 kg and a speed of 25.0 m/s at point B where the track radius is 10 m. A: What is the maximum speed the car can have at point c, radius 19.6 m, for the gravitational force ...
78. ### Physics

A car of mass 720 kg travels round a horizontal, semicircular racetrack of radius 200 m, at a constant speed of 48 km/h. What is the sideways component of the force exerted by the track on the car’s tyres?
79. ### physics

A cart of mass 223 g is placed on a frictionless horizontal air track. A spring having a spring constant of 10.20 N/ m is attached between the cart and the left end of the track. When in equilibrium, the cart is located 11.0 cm from the left end of the track. If the cart is ...
80. ### physics

A block with a mass of 0.5kg is pushed against a horizontal spring of negligible mass and spring constant 450 N/m until the spring is compressed a distance x. When it is released, the block travels along a frictionless, horizontal surface to the bottom of a verticle circular ...

a railroad handcar is moving along striaght, fricionless tracks. In each of the following cases the car initially has a total mass (car and contents of magniude 4.00 m/s^1. Find the final velocity of the car in each of the three cases. A) a 40.0 kg mass is thown sideways out ...
82. ### Physics

A perforated bead of mass 37g moves on a frictionless horizontal circular track of radius R=0.65m. The track runs through the bead. When the bead is at rest in the horizontal position, it is tied to a spring at the centre of the track. The unstretched length of the spring is R...
83. ### physics

A cannon is mounted on a railroad car. The cannon shoots a 1.75 kg ball with a muzzle velocity if 300 m/s. The cannon and the railroad car together have a mass of 4500 kg. if the ball, cannon, and railroad car are initially at rest, what is the recoil velocity of the car and ...
84. ### Physics

A freight car with a mass of 29,000 kg rolls down an inclined track through a vertical distance of 2.8 m. At the bottom of the incline, on a level track, the car collides and couples with an identical freight car that was at rest. What percentage of the initial kinetic energy ...
85. ### physics

A 2.24 kg mass on a frictionless horizontal track is attached to the end of a horizontal spring whose force constant is 4.45 N/m. The mass is displaced 3.06 m to the right from its equilibrium position and then released, which initiates simple harmonic motion. How many times ...
86. ### physics

A railroad car of mass 2.7 104 kg moving at 3.50 m/s collides and couples with two coupled railroad cars, each of the same mass as the single car and moving in the same direction at 1.20 m/s. (a) What is the speed of the three coupled cars after the collision? m/s (b) How much...
87. ### physics

A railroad car of mass 2.3*10^4 kg moving at 4.00 m/s collides and couples with two coupled railroad cars, each of the same mass as the single car and moving in the same direction at 1.20 m/s. (a) What is the speed of the three coupled cars after the collision? (b) How much ...
88. ### Physics

A railroad car with a mass of 1.93 104 kg moving at 3.24 m/s joins with two railroad cars already joined together, each with the same mass as the single car and initially moving in the same direction at 1.16 m/s. (a) What is the speed of the three joined cars after the ...
89. ### Physics

A railroad car with a mass of 1.91 multiplied by 104 kg moving at 2.86 m/s joins with two railroad cars already joined together, each with the same mass as the single car and initially moving in the same direction at 1.40 m/s. What is the speed of the three joined cars after ...
90. ### now for my physics hw..

A railroad car with a mass of 1.99 104 kg moving at 2.80 m/s joins with two railroad cars already joined together, each with the same mass as the single car and initially moving in the same direction at 1.52 m/s. (a) What is the speed of the three joined cars after the ...
91. ### Physics

A railroad car with a mass of 1.86 104 kg moving at 2.80 m/s joins with two railroad cars already joined together, each with the same mass as the single car and initially moving in the same direction at 1.40 m/s. (a) What is the speed of the three joined cars after the ...
92. ### physics

A mass M = 5 kg moves with an initial speed v = 3 on a level frictionless air track. The mass is initially a distance D = 0.250 m away from a spring with k = 844 N/m, which is mounted rigidly at one end of the air track. The mass compresses the spring a maximum distance d, ...
93. ### physics

A cart of mass 223 g is placed on a frictionless horizontal air track. A spring having a spring constant of 10.20 N/ m is attached between the cart and the left end of the track. When in equilibrium, the cart is located 11.0 cm from the left end of the track. If the cart is ...
94. ### Physics

A block of mass 0.61kg starts from rest at point A and slides down a frictionless hill of height h. At the bottom of the hill it slides across a horizontal piece of track where the coefficient of kinetic friction is 0.40. This section (from points B to C) is 4.73m in length. ...
95. ### gotta have answer by 11:59 tonight!!!

A railroad car with a mass of 1.99 104 kg moving at 2.80 m/s joins with two railroad cars already joined together, each with the same mass as the single car and initially moving in the same direction at 1.52 m/s. (a) What is the speed of the three joined cars after the ...
96. ### physics

A block of mass 0.78kg starts from rest at point A and slides down a frictionless hill of height h. At the bottom of the hill it slides across a horizontal piece of track where the coefficient of kinetic friction is 0.29. This section (from points B to C) is 4.08m in length. ...
97. ### Physics

A roller coaster car of mass 1000kg is riding along a track from point A to point C. (point A is 75m high, B is 50m high and C is 100m high, so that there are a total of three hills.) the final velocity at point C is 10m/s a) Assume no friction what is the speed of the car at ...
98. ### physics

A railroad car with a mass of 1.98 ✕ 104 kg moving at 2.92 m/s joins with two railroad cars already joined together, each with the same mass as the single car and initially moving in the same direction at 1.54 m/s. (a) What is the speed of the three joined cars after the ...
99. ### Physics

A roller-coaster car speeds down a hill past point A where R1 = 9.8 m and then rolls up a hill past point B where R2 = 15.8 m (R1 and R2 represent the radiuses/ radii) The car has a speed of 18.6 m/s at point A. if the track exerts a normal force on the car of 2.16 104 N at ...
100. ### Physics

A roller-coaster car speeds down a hill past point A where R1 = 8.2 m and then rolls up a hill past point B where R2 = 15.4 m, as shown below. (a) The car has a speed of 21.0 m/s at point A. if the track exerts a normal force on the car of 2.30 ✕ 104 N at this point, ...