1. A bullet shot horizontally from a gun A. strikes the ground much later than one dropped vertically from the same point at instant

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1 Name Period Date Concepts 1. A bullet shot horizontally from a gun A. strikes the ground much later than one from the same point at the same B. never strikes the ground C. strikes the ground at approximately the same time as one from the same point at the same D. travels in a straight line E. strikes the ground much sooner than one dropped from the same point at the same 2. The block shown moves with constant velocity on a horizontal surface. Two of the forces on it are shown. A frictional force exerted by the surface is the only other horizontal force on the block. The frictional force is: A. B. 2N, leftward C. 2N, rightward D. slightly more than 2N, leftward E. slightly less than 2N, leftward 3. A ball with a weight of 1.5 N is thrown at an angle of 3 above the horizontal with an initial speed of m/s. At its highest point, the net force on the ball is: B. zero C. 9.N, up D. 9.N, down E. 1.5N, down A. 9.N, 3 below horizontal. You stand on a spring scale on the floor of an elevator. Of the following, the scale shows the highest reading when the elevator: A. moves downward with increasing speed B. moves upward with decreasing speed C. remains stationary D. moves downward with decreasing speed E. moves upward at constant speed 5. A heavy ball is suspended as shown. A quick jerk on the lower string will break that string but a slow pull on the lower string will break the upper string. The first result occurs because: A. the force is too small to move the ball B. action and reaction is operating C. the ball has too much energy D. air friction holds the ball back E. the ball has inertia 6. A car enters a spiral track and maintains the same aneous speed throughout the course. The dotted line indicates the path travelled by the car. The observer is at the origin of the x-y coordinate system shown beside the track. Which position shows the car with the largest centripetal acceleration? Choose E if the centripetal acceleration is the same at all locations. 7. For the previous question, which statement is true about the car s motion at position C? A. vx is negative, vy is negative B. vx is positive, vy is negative C. vx is negative, D. vx is positive, E. vx is negative, vy is zero. Acceleration is always in the direction A. of the net force B. of the initial velocity C. of the final velocity D. of the displacement E. opposite to the frictional force 9. The velocity of a toy is given by vx =.5t 2 and vy=7; positions are in meters, time is in seconds. Which statement best describes the forces acting on the car? A. Fx is increasing; Fy is zero B. Fx is zero; Fy is zero C. Fx is decreasing; Fy is increasing D. Fx is constant; Fy is decreasing E. Fx is constant; Fy is zero 1. What information can NOT be known or calculated from these equations in the previous question? A. The toy s vertical displacement over a given time. B. The magnitude of the toy s initial velocity C. The magnitude of the toy s jerk. D. The moment when it comes to rest horizontally E. The toy s initial position Quiz- Intro to Newton s Laws & 2D Motion 1 1/23/1

2 Name Period Date Graphs 1. The vertical and horizontal velocity of a 5. kg projectile is graphed over time. a. Calculate the vertical acceleration of the object from this data. b. When is the object at the largest vertical distance from the observer? c. Calculate the magnitude of the velocity at 2.6 seconds. d. Calculate the total displacement of the projectile for the time shown on the graph. Velocity, m/s Vy Vx e. Calculate the net force acting on the projectile at t=3.5 seconds. 2. The acceleration of a cart for different masses is graphed. The total force remains the same for all trials. a. Estimate the net force acting on the cart. b. Estimate the acceleration of the cart for a total mass of 2. kg. 3. The position of an erratic particle is graphed relative to a stationary observer. Acceleration, m/s/s Mass, kg 1 a. Estimate the average velocity from t= to t=1.7 second. 2 b. Calculate the average acceleration from t=. second to t=2. seconds. Position, m c. Which statement is most correct about the particle s motion at t=1 second? A. It is moving toward the observer B. It s velocity is positive C. It is speeding up D. All of these statements are true E. None of these statements are true. Quiz- Intro to Newton s Laws & 2D Motion 2 1/23/1

3 Name Period Date Calculations Quiz: 2D Motion Provide answers with the correct precision and units (1) A ball is thrown horizontally from the top of a 2. m high hill. It strikes the ground at an angle of 5.. a. Calculate the time it took the ball to reach the ground. b. With what speed was it thrown? (2) The position of a 7. kg object in the x-y plane is given by the expressions: x = ( 3.)t 2 +. and y = (.)t Positions are in meters and time is in seconds. a. Calculate the magnitude of the object s position vector at t=3. seconds. b. Calculate the net force on the particle at t=3. seconds. (3) Two carts, connected by a light-weight rod, are rolling toward a motion sensor with an initial speed of 1. m/s. Cart 1 has a fan attached to it which pushes toward the right. The joined carts are slowing consistently with an acceleration of magnitude. m/s 2. The masses are: M1=.5 kg, M2=.7 kg. a. Calculate the net force acting on cart 1. b. Calculate the force of the fan, Ffan, on cart 1. c. Calculate the displacement of the carts from their original position to the position at which they change direction. () A panda of mass 5 kg starts at a height of h=7. m on a hill tilted to an angle of θ=3. Assume frictional forces on the hill are negligible. a. Calculate the normal force of the hill on the panda. b. Calculate the acceleration of the panda down the hill. c. Calculate how much time it will take the panda to reach the bottom of the hill. Quiz- Intro to Newton s Laws & 2D Motion 3 1/23/1

4 Name Period Date Concepts 1. C A bullet shot horizontally from a gun A. strikes the ground much later than one B. never strikes the ground C. strikes the ground at approximately the same time as one from the same point at the same from the same point at the same D. travels in a straight line E. strikes the ground much sooner than one dropped from the same point at the same 2. B The block shown moves with constant velocity on a horizontal surface. Two of the forces on it are shown. A frictional force exerted by the surface is the only other horizontal force on the block. The frictional force is: A. B. 2N, leftward C. 2N, rightward D. slightly more than 2N, leftward E. slightly less than 2N, leftward 3. E A ball with a weight of 1.5 N is thrown at an angle of 3 above the horizontal with an initial speed of m/s. At its highest point, the net force on the ball is: B. zero C. 9.N, up D. 9.N, down E. 1.5N, down A. 9.N, 3 below horizontal. D You stand on a spring scale on the floor of an elevator. Of the following, the scale shows the highest reading when the elevator: A. moves downward with increasing speed B. moves upward with decreasing speed C. remains stationary D. moves downward with decreasing speed E. moves upward at constant speed 5. E A heavy ball is suspended as shown. A quick jerk on the lower string will break that string but a slow pull on the lower string will break the upper string. The first result occurs because: A. the force is too small to move the ball B. action and reaction is operating C. the ball has too much energy D. air friction holds the ball back E. the ball has inertia E-the inertia of the ball resists a sudden change(acceleration) 6. D A car enters a spiral track and maintains the same aneous speed throughout the course. The dotted line indicates the path travelled by the car. The observer is at the origin of the x-y coordinate system shown beside the track. Which position shows the car with the largest centripetal acceleration? Choose E if the centripetal acceleration is the same at all locations. D-tightest curve = largest direction change per moment 7. A For the previous question, which statement is true about the car s motion at position C? A. v x is negative, v y is negative B. vx is positive, vy is negative C. vx is negative, D. vx is positive, E. vx is negative, vy is zero. A Acceleration is always in the direction A. of the net force B. of the initial velocity C. of the final velocity D. of the displacement E. opposite to the frictional force 9. A The velocity of a toy is given by vx =.5t 2 and vy=7; positions are in meters, time is in seconds. Which statement best describes the forces acting on the car? A. F x is increasing; F y is zero B. Fx is zero; Fy is zero C. Fx is decreasing; Fy is increasing D. Fx is constant; Fy is decreasing E. Fx is constant; Fy is zero a x=t; gets bigger each second with time; a y=; zero net force 1. E What information can NOT be known or calculated from these equations in the previous question? A. The toy s vertical displacement over a given time. B. The magnitude of the toy s initial velocity C. The magnitude of the toy s jerk. D. The moment when it comes to rest horizontally E. The toy s initial position Quiz- Intro to Newton s Laws & 2D Motion 1/23/1

5 Name Period Date Graphs 1. The vertical and horizontal velocity of a 5. kg projectile is graphed over time. a. 11 m/s 2 Calculate the vertical acceleration of the object from this data. slope of V y graph = 3.5= 11 m/s 2 b. 3.5 sec When is the object at the largest vertical distance from the observer? Moving up for most of trip; farthest away at 3.5 sec and then starts coming back down. c. 1 m/s Calculate the magnitude of the velocity at 2.6 seconds. v x 2 +v y 2 =v 2 à =v 2 à v= 1 m/s d. 29 m Calculate the total displacement of the projectile for the time shown on the graph. x=(-1)()=- m y=1/2()(3.5) 1/2(.5)(5) = 6.75 à meters total e. 55 N* Calculate the net force acting on the projectile at t=3.5 seconds. F=ma = 5 kg 11* = 55 N; *dependent upon answer for (a) 2. The acceleration of a cart for different masses is graphed. The total force remains the same for all trials. a. 3 N Estimate the net force acting on the cart. F=ma à I just picked a point on the graph:.5kg 6 = 3 N; any two points on the curve should give about the same result. b. 1.5m/s 2 * Estimate the acceleration of the cart for a total mass of 2. kg. Use your equation above: 3N = 2kg aà a=1.5 m/s 2 ; or notice that at 1 kg the acceleration is 3 m/s 2 so twice the mass would give ½ as much acceleration = 1.5 m/s 2 *answer depends on (a) value or work must be shown. 3. The position of an erratic particle is graphed relative to a stationary observer. Velocity, m/s Acceleration, m/s/s Vy Vx Mass, kg 1 a. ZERO Estimate the average velocity from t= to t=1.7 second. Basically a slope line from to 1.7 = which follows right along x-axis = ZERO; or notice that it ends up where it started = ZERO average velocity. b. 2m/s 2 ±5 Calculate the average acceleration from t=. second to t=2. seconds. Need to find the aneous slope at each moment and then - calculate the change in these slopes over the time in question (1.6 seconds) -1 at. sec slope ( 1 1)/(1.1.)= -3 m/s at 2. sec slope +(1 )/(2. 2) =.5 a= v/ t =.5 ( 3)/(2..) = 3. 2 m/s 2 *Very sensitive to actual values chosen; Could probably be ±5 for value IF WORK SHOWN c. E Which statement is most correct about the particle s motion at t=1 second? A. It is moving toward the observer B. It s velocity is positive C. It is speeding up D. All of these statements are true Very tricky because it s behind the observer. It is getting farther away, even though velocity is negative. The slope is gradually decreasing too, so it s also slowing. E. None of these statements are true. Quiz- Intro to Newton s Laws & 2D Motion 5 1/23/1 Position, m 2 2.

6 Name Period Date Calculations Quiz: 2D Motion Provide answers with the correct precision and units (1) A ball is thrown horizontally from the top of a 2. m high hill. It strikes the ground at an angle of 5.. a. 2.2 sec Calculate the time it took the ball to reach the ground. y=1/2at 2 +v t+y à =1/2( 9.)t 2 +2 à ( 2)(2)/( 9.) = t 2 à t= 2.2 sec b. 19. m/sec With what speed was it thrown? If it hits at a 5 angle, then v x=v y; v x never changed so if you know v y at bottom, you automatically know v x at start. It was thrown horizontally, so v x is the entire throw velocity. v y = v o + gt = gt = = 19. m/s v x=v y at bottom = v overall at launch= 19. m/s (2) The position of a 7. kg object in the x-y plane is given by the expressions: x = 3.t 2 +. and y =.t Positions are in meters and time is in seconds. a. 23 m Calculate the magnitude of the object s position vector at t=3. seconds. x 2 +y 2 =r 2 ; x= 3(3 2 )+=-19; y=(3)= m à r=22.5 b. 2 N Calculate the net force on the object at t=3. second. v x = 6t; a x= 6; (a y=); F net=ma à 7 ( 6) = 2 N (3) Two carts, connected by a light-weight rod, are rolling toward a motion sensor with an initial speed of 1. m/s. Cart 1 has a fan attached to it which pushes toward the right. The joined carts are slowing consistently with an acceleration of magnitude. m/s 2. The masses are: M1=.5 kg, M2=.7 kg. a N Calculate the net force acting on cart 1. F net=ma =.5. = +.22 N; acceleration is toward and slowing = positive value, relative to observer. b N Calculate the force of the fan, Ffan, on cart 1. Have to figure out forces on cart 2 because the rod is the ONLY force on it; cart 1 has too many force-variables to start with it. Cart 2: F net=ma = (.7)(.) =.3 N Cart 2: F net=f rod; (only one relevant force on cart 2) Cart 1: F net=f fan F rod à.22 = F fan.3 à F fan=.53 N (Force of rod on cart one is TOWARD the sensor; so it s negative) c. 1.1 m Calculate the displacement of the carts from their original position when they change direction. This happens when its aneous velocity is zero: v 2 =v 2 o +2a x à 2 =( 1) 2 +2(.)( x)à x= 1.13 m () A panda of mass 5 kg starts at a height of h=7. m on a hill tilted to an angle of θ=3 and slides down. Assume frictional forces on the hill are negligible. a. 66 N Calculate the normal force of the hill on the panda. F net(perpendicular to hill)= F net =F normal F g F g =mgcos(θ)=(5)(9.)cos(3)=656 N=F normal Fn θ Fg b. 6. m/s 2 Calculate the acceleration of the panda down the hill. Acceleration along hillà F net=ma & F net= F g =mgsin(θ) ma= mgsin(θ)à a=gsin(θ)=6.3 m/s 2 c. 1.9 sec Calculate how much time it will take the panda to reach the bottom of the hill. d(ramp distance)=1/2at 2 +v t+d à d=1/2at 2 +d o Distance along ramp = h/sin(θ)=11. m =1/2( 6.3)at à 11. = ½( 6.3)t 2 à t= 1.9 sec Fg Fg Quiz- Intro to Newton s Laws & 2D Motion 6 1/23/1