Answers edited by Morgan

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• An object with a mass of `15 kg` is on a ramp at an incline of `pi/8`. If the object is being pushed up the ramp with a force of `7 N`, what is the minimum coefficient of static friction needed for the object to remain put?
  
• A hockey player of mass 50kg runs at 20 m/s toward another player of 40kg, moving at -10 m/s. They collide. What are the final velocities of the players?
  
• A hat weighing `5"N"` is placed on a hook `1.5"m"` above the ground. What is the potential energy of the hat?
  
• A force field is described by `<F_x,F_y,F_z> = < x , z, y >`. Is this force field conservative?
  
• A ball with a mass of `256 g` is projected vertically by a spring loaded contraption. The spring in the contraption has a spring constant of `36 (kg)/s^2` and was compressed by `12/4 m` when the ball was released. How high will the ball go?
  
• An object with a mass of `5 kg` is on a plane with an incline of `pi/8`. If the object is being pushed up the plane with `8 N` of force, what is the net force on the object?
  
• A lamp hangs from the ceiling at a height of 2.9 m. If the lamp breaks and falls to the floor, what is its impact speed?
  
• What torque would have to be applied to a rod with a length of `4 m` and a mass of `3 kg` to change its horizontal spin by a frequency of `5 Hz` over `1 s`?
  
• How do you find the derivative of `root3((6x+7))`?
  
• A wrench with a length of `24 cm` is being used to unscrew a `3 cm` bolt. If a torque of `7 Nm` is needed to overcome the friction keeping the bolt in place, what is the minimum torque that must be applied to the wrench to unscrew the bolt?
  
• An object with a mass of `5 kg` is pushed along a linear path with a kinetic friction coefficient of `u_k(x)= x+xsinx`. How much work would it take to move the object over `x in [0, 8pi]`, where x is in meters?
  
• A `3.0*10^-3` kg truck traveling at 20.0 m/s in a test laboratory collides into a wall and comes to rest in 0.10 s. What is the magnitude of the average force acting on the truck during the collision?
  
• How do you integrate `int (x^2 - 8x + 44) / ((x + 2) (x - 2)^2)` using partial fractions?
  
• How do you integrate `int x^2e^x` from 0 to 1 by integration by parts method?
  
• How do you evaluate `intsin(2x)/sin(x)dx`?
  
• An object, previously at rest, slides `7 m` down a ramp, with an incline of `(pi)/3`, and then slides horizontally on the floor for another `3 m`. If the ramp and floor are made of the same material, what is the material's kinetic friction coefficient?
  
• A 0.1 g spider is suspended from a thread. What is the tension in the thread?
  
• An object with a mass of `8 kg` is on a plane with an incline of `- pi/12`. If it takes `8 N` to start pushing the object down the plane and `2 N` to keep pushing it, what are the coefficients of static and kinetic friction?
  
• How do you tell `"S"_"N"1` and `"S"_"N"2` reactions apart?
  
• If I throw an 18g dart from a height of 70" to a target that is 77" away & 68" high, and it takes .24 seconds to get there. Approx how heavy a dart of similar design would be required to hit the target if it's 3" further away using the same arm tempo?
  
• What is the angle between `<-1,8,6 >` and `< -6,3,0>`?
  
• An object with a mass of `3 kg` is traveling in a circular path of a radius of `2 m`. If the object's angular velocity changes from `2 Hz` to `16 Hz` in `5 s`, what torque was applied to the object?
  
• What is the angular velocity in radians per second of a flywheel that spins 4820 revolutions per minute?
  
• An object with a mass of `5 kg` is revolving around a point at a distance of `2 m`. If the object is making revolutions at a frequency of `4 Hz`, what is the centripetal force acting on the object?
  
• A rock is dropped from rest from the roof of a building 100 m high. What is the velocity of the rock at the moment it reaches the ground? How long does it take to hit the ground?
  
• How does an NMR spectrometer work?
  
• Question #4b2cc
  
• A ball with a mass of `150 g` is projected vertically by a spring loaded contraption. The spring in the contraption has a spring constant of `24 (kg)/s^2` and was compressed by `4/3 m` when the ball was released. How high will the ball go?
  
• An object of mass 16 kg is held in place by an applied force F and a pulley system as shown in the figure.  Find the tension T4.  Hint draw a free body diagram for the top pulley and the bottom pulley?
  
• What are the main intermolecular forces found in a liquid sample of `CBr_4`?
  
• How do you find the local max and min for `y=2x^3 - 5x^2 - 4x + 7`?
  
• How do you tune a cello?
  
• Question #3df20
  
• Two charges of `9 C` and `2 C` are positioned on a line at points `4` and `-4`, respectively. What is the net force on a charge of `3 C` at `-2`?
  
• An object with a mass of `110 g` is dropped into `750 mL` of water at `0^@C`. If the object cools by `70 ^@C` and the water warms by `5 ^@C`, what is the specific heat of the material that the object is made of?
  
• What is the minimum speed needed for a 2 kg mass to stay in motion in a vertical circle of radius 1.45 m?
  
• What is the cross product of `(- 4 i - 5 j + 2)` and `(i + j -7k)`?
  
• A ball with a mass of `12 kg` moving at `8 m/s` hits a still ball with a mass of `15 kg`. If the first ball stops moving, how fast is the second ball moving? How much kinetic energy was lost as heat in the collision?
  
• Question #6e7c7
  
• An object, previously at rest, slides `4 m` down a ramp, with an incline of `pi/3`, and then slides horizontally on the floor for another `9 m`. If the ramp and floor are made of the same material, what is the material's kinetic friction coefficient?
  
• A force field is described by `<F_x,F_y,F_z> = < x +y , 2z-y, 2y -z >`. Is this force field conservative?
  
• A ball with a mass of `420 g` is projected vertically by a spring loaded contraption. The spring in the contraption has a spring constant of `28 (kg)/s^2` and was compressed by `9/6 m` when the ball was released. How high will the ball go?
  
• A projectile is shot at an angle of `pi/3` and a velocity of `6 m/s`. How far away will the projectile land?
  
• A ball with a mass of `7 kg` and velocity of `4 m/s` collides with a second ball with a mass of `2 kg` and velocity of `- 6 m/s`. If `15%` of the kinetic energy is lost, what are the final velocities of the balls?
  
• Question #8685a
  
• An object with a mass of `8 kg` is pushed along a linear path with a kinetic friction coefficient of `u_k(x)= 5x^2-x+1`. How much work would it take to move the object over #x in [2, 3], where x is in meters?
  
• Does a car accelerate when it goes around a corner at a constant speed?
  
• How many mols are in 8.00 g `BeF_2`?
  
• How much work would it take to push a `1 kg` weight up a `4 m` plane that is at an incline of `pi / 4`?
  
• How does the smoothness of a surface affect the size of friction?
  
• A container with a volume of `4 L` contains a gas with a temperature of `270^o K`. If the temperature of the gas changes to `420^o K` without any change in pressure, what must the container's new volume be?
  
• An object, previously at rest, slides `15 m` down a ramp, with an incline of `pi/3`, and then slides horizontally on the floor for another `10 m`. If the ramp and floor are made of the same material, what is the material's kinetic friction coefficient?
  
• Two charges of `3 C` and `-7 C` are positioned on a line at points `6` and `5`, respectively. What is the net force on a charge of `2 C` at `-2`?
  
• A solid disk, spinning counter-clockwise, has a mass of `6 kg` and a radius of `3 m`. If a point on the edge of the disk is moving at `5/2 m/s` in the direction perpendicular to the disk's radius, what is the disk's angular momentum and velocity?
  
• A box with an initial speed of `5 m/s` is moving up a ramp. The ramp has a kinetic friction coefficient of `5/4` and an incline of `(3 pi )/4`. How far along the ramp will the box go?
  
• An object, previously at rest, slides `9 m` down a ramp, with an incline of `(pi)/3`, and then slides horizontally on the floor for another `19 m`. If the ramp and floor are made of the same material, what is the material's kinetic friction coefficient?
  
• How much work does it take to raise a `6 kg` weight `21 m`?
  
• How much work does it take to push an object with a mass of `4 kg` up a `9 m` ramp, if the ramp has an incline of `(5pi)/12` and a kinetic friction coefficient of `8`?
  
• A wrench with a length of `20 cm` is used to unscrew a `3/2 cm` bolt. If a torque of `8 Nm` is needed to overcome the friction keeping the bolt in place, what is the minimum torque that must be applied to the wrench to unscrew the bolt?
  
• Question #fee78
  
• Question #2e2cc
  
• What are the advantages and disadvantages of mass spectroscopy?
  
• A wrench with a length of `42 cm` is being used to unscrew a `7/2 cm` bolt. If a torque of `32 Nm` is needed to overcome the friction keeping the bolt in place, what is the minimum torque that must be applied to the wrench to unscrew the bolt?
  
• What is the average speed of an object that is moving at `18 m/s` at `t=0` and accelerates at a rate of `a(t) =t-8` on `t in [1,4]`?
  
• An object with a mass of `4 kg` is pushed along a linear path with a kinetic friction coefficient of `u_k(x)= 5+tanx`. How much work would it take to move the object over `x in [(pi)/12, (pi)/4]`, where x is in meters?
  
• How do you solve `8h ^ { 2} - 8h + 1= 0`?
  
• An object with a mass of `18 kg` is on a plane with an incline of `-(5 pi)/12`. If it takes `9 N` to start pushing the object down the plane and `4 N` to keep pushing it, what are the coefficients of static and kinetic friction?
  
• A block weighing `14 kg` is on a plane with an incline of `pi/12` and friction coefficient of `1/5`. How much force, if any, is necessary to keep the block from sliding down?
  
• The rate of rotation of a solid disk with a radius of `8 m` and mass of `2 kg` constantly changes from `2 Hz` to `8 Hz`. If the change in rotational frequency occurs over `12 s`, what torque was applied to the disk?
  
• Question #a9e31
  
• A wrench with a length of `20 cm` is used to unscrew a `5/2 cm` bolt. If a torque of `12 Nm` is needed to overcome the friction keeping the bolt in place, what is the minimum torque that must be applied to the wrench to unscrew the bolt?
  
• Question #4acab
  
• A ball with a mass of `2 kg` and velocity of `2 m/s` collides with a second ball with a mass of `1 kg` and velocity of `- 4 m/s`. If `20%` of the kinetic energy is lost, what are the final velocities of the balls?
  
• How do you name alkenes and alkynes?
  
• Question #bb8aa
  
• A 1.0 kg object moving at 10 m/s 30° N of E collides centrally with a 2.0 kg object moving at 5 m/s 30° S of W. If the collision is inelastic, what is the velocity of the combined objects after collision?
  
• A ball with a mass of `7 kg` and velocity of `2 m/s` collides with a second ball with a mass of `6 kg` and velocity of `- 3 m/s`. If `75%` of the kinetic energy is lost, what are the final velocities of the balls?
  
• Question #b567b
  
• Two charges of `-6 C` and `-3 C` are positioned on a line at points `-5` and `8`, respectively. What is the net force on a charge of `4 C` at `2`?
  
• A force field is described by `<F_x,F_y,F_z> = < xy , xy-x, 2y -zx >`. Is this force field conservative?
  
• A projectile is shot at an angle of `pi/8` and a velocity of `10 m/s`. How far away will the projectile land?
  
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