Net force Transitional Reasoning Download PDF

Questions

1. 1.

   During an aerodynamics calibration test, a model glider is mounted on a low-friction horizontal track aligned along an east-west line. The wind tunnel produces an aerodynamic drag force of 54 N directed toward the east, while a secondary exhaust jet exerts a force of 18 N directed toward the east. Simultaneously, the glider's onboard propulsion motor generates a force of 85 N directed toward the west. What is the net horizontal force currently acting on the glider, and what additional force must be applied along the track to achieve horizontal equilibrium?

   • A) Net force is 13 N directed west; an additional force of 13 N directed east is required.
   • B) Net force is 13 N directed east; an additional force of 13 N directed west is required.
   • C) Net force is 49 N directed west; an additional force of 49 N directed east is required.
   • D) Net force is 157 N directed west; an additional force of 157 N directed east is required.
2. 2.

   An exploration sled travels eastward across a flat ice sheet at a steady speed under a forward propulsion force of 220 N that balances 220 N of friction and drag. Upon entering a patch of packed snow, the total opposing resistive force increases to 310 N while the forward propulsion force remains unchanged at 220 N. What is the magnitude and direction of the net force acting on the sled in the snow patch, and how does this net force affect the sled's motion?

   • A) 90 N eastward; the sled accelerates and speeds up.
   • B) 530 N westward; the sled immediately stops moving.
   • C) 90 N westward; the sled slows down while continuing to move eastward.
   • D) 0 N; the sled maintains its steady eastward speed.
3. 3.

   A scientific payload resting on a frictionless horizontal test track is acted upon by three horizontal forces along the same line: an applied magnetic drive force of 80 N directed east, an electromagnetic damping force of 35 N directed west, and a mechanical spring pull of 45 N directed west. A student claims that the payload will accelerate eastward because the 80 N drive force is the single greatest individual force acting on the object. Which statement correctly evaluates the net force acting on the payload and the student's claim?

   • A) The net force is 45 N directed east because only the damping force directly opposes the drive force; therefore, the student's claim is correct.
   • B) The net force is 80 N directed east because the single greatest individual force dictates the overall net force; therefore, the student's claim is correct.
   • C) The net force is 0 N because the two westward forces fully balance the eastward drive force; therefore, the student's claim is incorrect.
   • D) The net force is 10 N directed west because the two opposing forces subtract from each other; therefore, the student's claim is incorrect.
4. 4.

   An automated vertical cargo lift carries equipment during a test trial. In Stage 1, the hoist cable pulls upward with a force of 850 N, while gravity pulls downward with 600 N and guide-rail friction exerts a downward resistance of 50 N. In Stage 2, the lift ascends at a steady, constant velocity of 2.5 m/s. What is the net force acting on the lift during Stage 1 and Stage 2, respectively?

   • A) 200 N upward in Stage 1, and 0 N in Stage 2
   • B) 200 N upward in Stage 1, and 650 N upward in Stage 2
   • C) 250 N upward in Stage 1, and 0 N in Stage 2
   • D) 200 N upward in Stage 1, and 200 N upward in Stage 2
5. 5.

   A vertical test rig evaluates the ascent performance of an experimental delivery drone carrying a scientific sensor package. The drone has a weight of 55 N and the sensor package has a weight of 15 N. During an ascent test, the drone's rotors generate a combined upward thrust of 98 N, while air resistance exerts a downward drag force of 12 N on the drone body and 4 N on the sensor package. What is the magnitude and direction of the net force acting on the combined drone-sensor system?

   • A) 28 N directed upward
   • B) 12 N directed downward
   • C) 12 N directed upward
   • D) 31 N directed upward
6. 6.

   Two tugboats pull a barge forward along a straight canal while water resistance opposes the motion. Tugboat A exerts a forward force of 12,000 N, Tugboat B exerts a forward force of 8,000 N, and water resistance exerts a backward force of 5,000 N. Tugboat B then reduces its forward force by half, while water resistance increases to 6,000 N and Tugboat A maintains its original force. By how much does the net forward force acting on the barge decrease as a result of these changes?

   • A) 3,000 N
   • B) 4,000 N
   • C) 5,000 N
   • D) 10,000 N
7. 7.

   A shipping crate is positioned on a flat horizontal floor while being hoisted by an overhead crane. In the vertical direction, Earth's gravity exerts a downward force of 500 N, while the crane pulls upward with 350 N and the floor exerts an upward normal force of 150 N. In the horizontal direction along a straight line, Tug A pulls the crate with a force of 85 N to the right, while Tug B pulls with 35 N to the left and kinetic friction exerts 20 N to the left. What is the magnitude and direction of the net force acting on the crate?

   • A) 30 N directed to the right
   • B) 50 N directed to the right
   • C) 65 N directed to the right
   • D) 0 N, as the applied forces maintain equilibrium
8. 8.

   During a dynamics lab trial, a motorized cart moves steadily toward the east along a straight horizontal test track. An internal drive system applies a forward propelling force of 52 N to the east, while a braking mechanism adds a retarding force of 20 N to the west. Taking into account a surface friction force of 14 N that opposes the cart's eastward motion, what is the magnitude and direction of the net horizontal force acting on the cart?

   • A) 18 N to the east
   • B) 18 N to the west
   • C) 32 N to the east
   • D) 46 N to the east
9. 9.

   A remote-controlled hovercraft on a frictionless test floor is subjected to four horizontal forces aligned with cardinal directions: 40 N directed north, 25 N directed south, 30 N directed east, and 10 N directed west. What is the magnitude of the net horizontal force acting on the hovercraft, and toward which general direction does it act?

   • A) 25 N, directed northeast
   • B) 35 N, directed northeast
   • C) 25 N, directed southwest
   • D) 105 N, directed northeast
10. 10.

    During a physics laboratory investigation, three students apply horizontal forces along the same line to a test cart resting on a frictionless track. Student 1 pulls the cart to the right with a force of 18 N, while Student 2 pulls to the left with a force of 7 N. If the resulting net force acting on the cart is measured to be 5 N directed to the left, what is the magnitude and direction of the force exerted by Student 3?

    • A) 16 N directed to the left
    • B) 16 N directed to the right
    • C) 6 N directed to the left
    • D) 6 N directed to the right