Questions and Answers
In a collision between a 50-ton bulldozer and a compact car, both vehicles experience the same force.
True
Find the net force acting on a 2 kg object if the net acceleration is 10 m/s².
20 N
What is the magnitude of the crate's resultant acceleration when two donkeys are pulling an 80 kg crate?
7.3 m/s²
The reading on the scale for a 6-foot-tall man who weighs 170 lbs in a downward accelerating elevator is ______.
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According to Newton's 2nd Law, ____ is the cause and _____ is the effect.
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Find the force exerted on a 6 kg spare helmet by the dashboard when a stunt car hits a wall.
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Determine the mass of an object given a 10 N force is applied to the North and a 5 N force is applied to the South with a constant acceleration of 2.0 m/s².
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The weight of a crate is down and the normal force of the floor on the crate is up. The weight is _____ to the normal force and the two forces ___ an interaction pair.
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Find the force exerted on a 500 kg motorcycle that accelerates from rest to 25 m/s over a time interval of 5.5 s.
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If a net force is acting on an object, then we can assume the object is being accelerated.
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What is the speed of a 5 kg object at t = 4 s if it is propelled from rest by a net force F given by F = 0.5t?
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What is the magnitude of the net force on a particle moving with speed v = bt² + c at time t = t1?
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Which string must be the strongest to prevent breaking when three blocks connected by strings are pulled?
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At which time is the force exerted by the elevator floor on a passenger the least during upward motion?
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Find the normal force of leaves on a 0.6 kg squirrel coming to rest after falling.
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What is the magnitude of the friction acting on a refrigerator sliding with constant velocity when a 300 N force is applied?
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Determine the mass of an object given the net force acting on it is 15 N and the acceleration is 5 m/s².
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What is the reading on the scale for a 686 N person accelerating upward at 4.9 m/s²?
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What is the tension in the cable pulling the 2500 kg elevator upward at a rate of 3.5 m/s²?
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The property of matter which is a measure of an object's resistance to motion is called?
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If a 5 kg object is being pushed with the same force as another object that has a mass of 12 kg, then what can we infer?
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When an object is moving with constant velocity, we can assume the external forces acting on the object sum to zero.
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Which spring is stretched the most when three blocks connected to identical springs are pulled?
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Which graph best represents the magnitude of the net force exerted on the object as a function of time?
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What is the tension in the string between blocks when a frictionless system is accelerated by an applied force F?
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What is the acceleration of a block of mass 3 kg pulled along a frictionless, horizontal surface with force shown as a function of time?
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What is the speed of a block of mass 3 kg at t = 2 s when pulled along a frictionless, horizontal surface?
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Study Notes
Collision and Impact Forces
- In a collision, all vehicles experience the same impact force regardless of their masses.
Newton's Second Law Applications
- Net force can be calculated using F = ma; for a 2 kg object with an acceleration of 10 m/s², the net force is 20 N.
- An object with a net force of 15 N and an acceleration of 5 m/s² has a mass of 3 kg.
Forces and Acceleration
- If two donkeys apply forces in different directions on an 80 kg crate, the resultant acceleration is 7.3 m/s².
- A 500 kg motorcycle accelerating to 25 m/s in 5.5 seconds experiences a friction force of 2273 N.
Elevator Dynamics
- An elevator accelerating downward decreases the scale reading; for a 170 lbs man, the reading is less than 170 lbs.
- When a person weighing 686 N is in an upward-accelerating elevator at 4.9 m/s², the scale reads 1029 N.
Object Motion and Forces
- A normal force is equal to the weight of an object resting on a surface, but they are not an interaction pair.
- When an object moves with constant velocity, it indicates that external forces sum to zero.
Friction and Resistance
- A 300 N force applied to a 1500 N refrigerator results in a friction force of 300 N as it slides with constant velocity.
- Inertia quantifies an object's resistance to changes in motion.
Acceleration Relations
- If a 5 kg object and a 12 kg object are pushed with the same force, the 5 kg object accelerates 2.4 times faster.
Mass and Force Relationships
- The mass of the elevator and occupants is 2500 kg, with tension in the cable calculated to be 33,275 N when accelerated at 3.5 m/s².
- For an object propelled by a net force of F = 0.5t, the speed at t = 4 s is 0.8 m/s.
Spring and Tension Systems
- Among connected blocks with springs and subjected to forces, the spring connected to the 3m mass stretches the most.
- Tension in a system of blocks connected with strings can be calculated relative to the applied force.
Problem-Solving with Forces
- A block of mass 3 kg experiences different accelerations and speeds based on the applied force, illustrating how to derive speed and acceleration from applied forces over time.
Newton's First Law Insights
- An object not accelerating implies it is either stationary or moving at a constant speed; this underpins the essence of Newton's First Law.
Force Relationships in Collisions
- During a collision with a wall, the force exerted can be calculated based on mass and deceleration of an object (e.g., a helmet striking a dashboard generates a force of 1140 N over 0.07 seconds).
Studying That Suits You
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Description
Test your knowledge with these flashcards covering key concepts in AP Physics C Mechanics. From understanding forces in collisions to calculating net forces, this quiz will reinforce your learning and help you prepare for exams. Perfect for anyone studying physics at an advanced level.
