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Regents Physics Review #1 Vectors

Regents Physics Review #1 Vectors. Scalar Vector. Magnitude(size) only Magnitude(size) AND Direction. Distance Displacement Speed Velocity Mass Weight Work Force Momentum. Scalar is to vector as speed is to velocity

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Regents Physics Review #1 Vectors

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  1. Regents Physics Review#1Vectors

  2. Scalar Vector Magnitude(size) only Magnitude(size) AND Direction Distance Displacement Speed Velocity Mass Weight Work Force Momentum

  3. Scalar is to vector as • speed is to velocity • (2) displacement is to distance • (3) displacement is to velocity • (4) speed is to distance

  4. What are the magnitudes of the horizontal and vertical components?

  5. A model airplane heads due east at 1.50 meters per second, while the wind blows due north at 0.70 meter per second. The scaled diagram below represents these vector quantities.(June 2011) 66 Using a ruler, determine the scale used in the vector diagram. [1] 67 On the diagram above, use a protractor and a ruler to construct a vector to represent the resultant velocity of the airplane. Label the vector R. [1] 68 Determine the magnitude of the resultant velocity. [1] 69 Determine the angle between north and the resultant velocity. [1]

  6. A dog walks 8.0 meters due north and then 6.0 meters due east. Using a metric ruler and the vector diagram, determine the scale used in the diagram. [1] On the diagram above, construct the resultant vector that represents the dog’s total displacement. [1] Determine the magnitude of the dog’s total displacement. [1]

  7. Calculate the magnitude of the component of the 60.-newton force that is parallel to the horizontal surface. [Show all work, including the equation and substitution with units.] [2]

  8. A baseball player runs 27.4 meters from the batter’s box to first base, overruns first base by 3.0 meters, and then returns to first base. Compared to the total distance traveled by the player, the magnitude of the player’s total displacement from the batter’s box is (1) 3.0 m shorter (2) 6.0 m shorter (3) 3.0 m longer (4) 6.0 m longer A child walks 5.0 meters north, then 4.0 meters east, and finally 2.0 meters south. What is the magnitude of the resultant displacement of the child after the entire walk? (1) 1.0 m (2) 5.0 m (3) 3.0 m (4) 11.0 m As the angle between two concurrent forces decreases, the magnitude of the force required to produce equilibrium (1) decreases (2) increases (3) remains the same

  9. Which is a vector quantity? (1) speed (2) work (3) mass (4) displacement A soccer player kicks a ball with an initial velocity of 10. meters per second at an angle of 30.° above the horizontal. The magnitude of the horizontal component of the ball’s initial velocity is (1) 5.0 m/s (2) 8.7 m/s (3) 9.8 m/s (4) 10. m/s

  10. Regents Physics Review#2Motion, Velocity, Acceleration (See Review Book P. 10-17)

  11. Velocity is the change in displacement per unit time. Velocity is a vector, it must include a direction such as +,-, left, right, up, down, north, south, etc. Speed is simply the change in distance over time regardless of direction. Speed is a scalar. Uniform Velocity = constant velocity; not changing. Average Velocity = Total displacement / Total time Acceleration = change in velocity over time. Acceleration is a vector.

  12. Equations from Reference Tables:

  13. Distance vs. Time graphs Distance Slope = velocity Time Straight line = constant velocity = NOT accelerating

  14. Distance vs. Time graphs Distance Slope = velocity = 0 Time Straight HORIZONTAL line = 0 velocity = NOT moving

  15. Distance vs. Time graphs Distance Slope = velocity Time Curved line = changing velocity = acceleration

  16. Velocity vs. Time graphs Velocity Slope = acceleration Time Straight line = uniform acceleration (e.g. gravity)

  17. A 25-newton weight falls freely from rest from the roof of a building. What is the total distance the weight falls in the first 1.0 second? (1) 19.6 m (3) 4.9 m (2) 9.8 m (4) 2.5 m If a car accelerates uniformly from rest to 15 meters per second over a distance of 100. meters, the magnitude of the car’s acceleration is (1) 0.15 m/s2 (2) 1.1 m/s2 (3) 2.3 m/s2 (4) 6.7 m/s2

  18. Vy= 0 Vx Vy Vy Vx Vx Vy Vy Vx Vx Projectile Motion When you throw an object into the air (projectile): 1. The X component of the velocity is constant (does not change) 2. The Y component of the velocity starts out large, slows down to 0, then increases back to where it started. 3. What goes up, must come down…in the same amount of time. This statement means that if it takes 4 seconds for an object to hit the ground after it is thrown, then the object must have taken 2 seconds to get to the top and 2 seconds to get back to the ground.

  19. V Vy = Vsin Θ Θ Vx = Vcos Θ

  20. Summary • For projectile motion, remember the following: • 1. Time up = Time down. • The projectile reaches its highest point midway through its • flight. (half the time & half the horizontal distance) • 3. At the highest point, the vertical velocity = 0 m/s • 4. Gravity affects only the vertical velocity. • 5. The horizontal velocity is constant. (stays the same) • 6. The shape of the path is a parabola.

  21. The diagram below represents a ball being kicked by a foot and rising at an angle of 30.0 from the horizontal. The ball has an initial velocity of 5.0 meters per second. [Neglect friction.] A. What is the magnitude of the horizontal component of the ball's initial velocity? (1) 2.5 m/s (2) 4.3 m/s (3) 5.0 m/s (4) 8.7 m/s B. As the ball rises, the vertical component of its velocity (I) decreases (2) increases (3) remains the same

  22. A rocket is launched at an angle of 60° to the horizontal. The initial velocity of the rocket is 500 meters per second. [Neglect friction.] A. The vertical component of the initial velocity is (1) 250 m/s (2) 433 m/s (3) 500 m/s (4) 1000 m/s B. Compared to the horizontal component of the rocket's initial velocity, the horizontal component after 10 seconds would be (1) less (2) greater (3) the same

  23. Time to “A” = 0.50 s Time to “B” = 1.00 s 60 Determine the magnitude of the horizontal component of the velocity of the car at point B. [Neglect friction.] [1] 61 Determine the magnitude of the vertical velocity of the car at point A. [1] 62 Calculate the magnitude of the vertical displacement, dy, of the car from point A to point B. [Neglect friction.] [Show all work, including the equation and substitution with units.] [2]

  24. 11 A ball is thrown vertically upward with an initial velocity of 29.4 meters per second. What is the maximum height reached by the ball? [Neglect friction.] (1) 14.7 m (2) 29.4 m (3) 44.1 m (4) 88.1 m

  25. Regents Physics Review #3 Newton’s Laws, Forces, Friction (See Review Book P.22-33)

  26. Newton’s First Law of Motion: The Law of Inertia An object will resist any change in its state of motion. An object at rest will stay at rest; an object in motion will stay moving in a straight line at a constant speed unless acted on by an unbalanced force. Mass is the measure of an object’s inertia. Newton’s Second Law of Motion: Force, Mass, and Acceleration An unbalanced force causes an object to accelerate: F = ma Equilibrium: All forces are balanced. Newton’s Third Law of Motion:Action and Reaction For every force there is an equal force in the opposite direction. Newton’s Law of Universal Gravitation: All matter attracts other matter. Fg = G m1 m2 / r2 .

  27. Weight is a force caused by gravity: F = ma F = mg On Earth, g = 9.81 m/s2 Friction is a force that opposes the motion of an object and depends upon the type of surfaces that are in contact with each other. Friction can be: “sliding” or “rolling” “static” or “kinetic” Each surface has its own coefficient of friction.

  28. An object on an inclined plane has several forces acting upon it: Weight, Normal Force, Force parallel to the plane, and Friction.

  29. 2. 1. 3. 4. • Force parallel to plane • Friction • Normal Force (perpendicular to plane • Weight

  30. Centripetal Force Inertiatends to keep the object in a straight line. Centripetal Force: Force toward the center of a circle. The result is circular motion. Inertia Centripetal Force

  31. 12 The diagram below represents a mass, m, being swung clockwise at constant speed in a horizontal circle. At the instant shown, the centripetal force acting on mass m is directed toward point (1) A (2) B (3) C (4) D

  32. 7 The magnitude of the centripetal force acting on an object traveling in a horizontal, circular path will decrease if the (1) radius of the path is increased (3) direction of motion of the object is reversed (2) mass of the object is increased (4) speed of the object is increased 8 The centripetal force acting on the space shuttle as it orbits Earth is equal to the shuttle’s (1) inertia (2) momentum (3) velocity (4) weight

  33. A student and the waxed skis he is wearing have a combined weight of 850 newtons. The skier travels down a snow--covered hill and then glides to the east across a snow-covered, horizontal surface. 53 Determine the magnitude of the normal force exerted by the snow on the skis as the skier glides across the horizontal surface. [1] 54–55 Calculate the magnitude of the force of friction acting on the skis as the skier glides across the snow-covered, horizontal surface. [Show all work, including the equation and substitution with units.] [2]

  34. 70–71 Calculate the elongation of the spring produced by the suspended 2.00-kilogram mass. [Show all work, including the equation and substitution with units.] [2] 72–73 Calculate the total elastic potential energy stored in the spring due to the suspended 2.00-kilogram mass. [Show all work, including the equation and substitution with units.] [2]

  35. 13 As shown in the diagram below, an open box and its contents have a combined mass of 5.0 kilograms. A horizontal force of 15 newtons is required to push the box at a constant speed of 1.5 meters per second across a level surface. The inertia of the box and its contents increases if there is an increase in the (1) speed of the box (2) mass of the contents of the box (3) magnitude of the horizontal force applied to the box (4) coefficient of kinetic friction between the box and the level surface

  36. Regents Physics Review #4 Momentum, Energy Work, Power

  37. Momentum: Mass x Velocity Momentum is a vector quantity because velocity is a vector. Formula: p = mv Law of Conservation of Momentum: Total momentum of a system is conserved…all the “pieces” of momentum must be accounted for and add up to the total you started with. Total Momentum before a collision = Total Momentum after a collision Impulse = Force x time J = Ft Impulse = change of momentum: Ft = mv Energy is the capacity to do work. Potential= “stored up” Kinetic = moving Work = a change in energy (potential or kinetic) Work = force x distance. Work can only be done if the force is in the same direction as the direction of motion! Power = work / time or “How fast you do work.”

  38. The diagram below represents two masses before and after they collide. Before the collision, mass mAis moving to the right with speed v, and mass mBis at rest. Upon collision, the two masses stick together. Write an expression for V’ (the velocity after the collision.)

  39. A 0.149-kilogram baseball, initially moving at 15 meters per second, is brought to rest in 0.040 second by a baseball glove on a catcher’s hand. The magnitude of the average force exerted on the ball by the glove is (1) 2.2 N (2) 2.9 N (3) 17 N (4) 56 N A 3.1-kilogram gun initially at rest is free to move. When a 0.015-kilogram bullet leaves the gun with a speed of 500. meters per second, what is the speed of the gun? (1) 0.0 m/s (2) 2.4 m/s (3) 7.5 m/s (4) 500. m/s

  40. A bicycle and its rider have a combined mass of 80. kilograms and a speed of 6.0 meters per second. What is the magnitude of the average force needed to bring the bicycle and its rider to a stop in 4.0 seconds? (1) 1.2 x102 N (2) 3.2 x102 N (3) 4.8 x102 N (4) 1.9 x103 N Calculate the magnitude of the impulse applied to a 0.75-kilogram cart to change its velocity from 0.50 meter per second east to 2.00 meters per second east. [Show all work, including the equation and substitution with units.] [2]

  41. Which statement describes the kinetic energy and total mechanical energy of a block as it is pulled at constant speed up an incline? (1) Kinetic energy decreases and total mechanical energy increases. (2) Kinetic energy decreases and total mechanical energy remains the same. (3) Kinetic energy remains the same and total mechanical energy increases. (4) Kinetic energy remains the same and total mechanical energy remains the same. Calculate the kinetic energy of a particle with a mass of 3.34 × 10-27 kilogram and a speed of 2.89 × 105 meters per second. [Show all work, including the equation and substitution with units.] [2]

  42. Which graph represents the relationship between the gravitational potential energy (GPE) of an object near the surface of Earth and its height above the surface of Earth?

  43. A ball is dropped from the top of a cliff. Which graph best represents the relationship between the ball’s total energy and elapsed time as the ball falls to the ground? [Neglect friction.]

  44. A 1200-kilogram car moving at 12 meters per second collides with a 2300-kilogram car that is waiting at rest at a traffic light. After the collision, the cars lock together and slide. Eventually, the combined cars are brought to rest by a force of kinetic friction as the rubber tires slide across the dry, level, asphalt road surface. Calculate the speed of the locked-together cars immediately after the collision. [Show all work, including the equation and substitution with units.] [2] Calculate the magnitude of the frictional force that brings the locked-together cars to rest. [Show all work, including the equation and substitution with units.] [2]

  45. The diagram below shows a toy cart possessing 16 joules of kinetic energy traveling on a frictionless, horizontal surface toward a horizontal spring. If the cart comes to rest after compressing the spring a distance of 1.0 meter, what is the spring constant of the spring? (1) 32 N/m (2) 16 N/m (3) 8.0 N/m (4) 4.0 N/m

  46. The diagram below represents a 155-newton box on a ramp. Applied force F causes the box to slide from point A to point B. What is the total amount of gravitational potential energy gained by the box? (1) 28.4 J (2) 279 J (3) 868 J (4) 2740 J

  47. A vertically hung spring has a spring constant of 150. newtons per meter. A 2.00-kilogram mass is suspended from the spring and allowed to come to rest. Calculate the elongation of the spring produced by the suspended 2.00-kilogram mass. [Show all work, including the equation and substitution with units.] [2] Calculate the total elastic potential energy stored in the spring due to the suspended 2.00-kilogram mass. [Show all work, including the equation and substitution with units.] [2]

  48. Regents Physics Review #5 Waves

  49. Waves • Transverse Wave • Longitudinal (Compression) Wave • Standing waves • Velocity = Frequency x Wavelength • Superposition, Phase • Reflection • Refraction • Normal • “Bend toward the Normal,” “Bend awwy from the Normal” • Diffraction • Polarization • Angle of Incidence = Angle of Reflection • Angle of Refraction • Index of Refraction • Spectrum

  50. Transverse Wave (Electromagnetic,Light) Wavelength Crest or Peak Valley or Trough

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