Conceptual physics chapter 4 4.2 study guide
A 10-N falling object encounters 10 N air resistance. The net force on the object is A) 0N B) 4N C) 6N D) 10N E) none of these
Answer: A Diff: 1
A force is a vector quantity because it has both A) magnitude and direction B) mass and acceleration C) action and reaction counterparts
Answer: A Diff: 1
A heavy block at rest is suspended by a vertical rope. When the block is accelerated upward by the rope tension A) increases B) decreases C) remains the same
Answer: A Diff: 1
An apple weighs 1 N. When held at rest above your head, the net force on the apple is A) 0N B) 0.1N C) 1N D) 9.8N E) none of these
Answer: A Diff: 1
The force required to maintain an object at a constant velocity in free space is equal to A) zero B) the mass of the object C) the weight of the object D) the force required to stop it E) none of these
Answer: A Diff: 2
The mass of a pet turtle that weighs 10 N is A) about 1 kg. B) about 10 kg. C) about 100 kg. D) about 1000 kg. E) none of these
Answer: A Diff: 2
A 10-kilogram block is pushed across a horizontal surface with a horizontal force of 20 N against a friction force of 10 N. The acceleration of the block in meters per second per second is A) 1 B) 2 C) 5 D) 10 E) none of these
Answer: A Diff: 3
A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is A) the same as the force on the 1-kg book B) 10 times as much C) one-tenth as much D) zero
Answer: B Diff: 1
A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is A) 200N B) 400N C) 800N D) 1600N E) none of these
Answer: B Diff: 1
An object is pulled northward by a force of 10 N and at the same time another force of 15 N pulls it southward. The magnitude of the resultant force on the object is A) 0 N B) 5 N C) 25 N D) 150 N
Answer: B Diff: 1
If an object's mass is decreasing while a constant force is applied to the object, the acceleration A) decreases B) increases C) remains
Answer: B Diff: 1
Whenever the net force on an object is zero, its acceleration A) may be less than zero B) is zero C) may be more than zero
Answer: B Diff: 1
Your car is coasting on level ground at 60 km/h and you apply the brakes until the car slows to 40 km/h. If you suddenly release the brakes now, the car tends to A) momentarily regain its higher initial speed B) continue moving at 40 km/h C) decrease in speed if no other forces act
Answer: B Diff: 1
A 1-kg rock that weighs 10 N is thrown straight upward at 20 m/s. Neglecting air resistance, the net force that acts on it when it is half way to the top of its path is A) less than 9.8N B) 9.8N C) more than 9.8N
Answer: B Diff: 2
A 10-N block and a 1-N block lie on a horizontal frictionless table. To provide them with equal horizontal acceleration, we would have to push with A) equal forces on each block B) 10 times as much force on the heavier block C) 1o squared or 100 times as much force on the heavier block D) 1/10 as much force on the heavier block E) none of these
Answer: B Diff: 2
A girl pulls on a 10-kg wagon with a constant horizontal force of 30N. If there are no other horizontal forces, what is the wagon's acceleration in meters per second per second? A) 0.3 B) 3.0 C) 10 D) 30 E) 300
Answer: B Diff: 2
A push on a 1-kg brick accelerates it. Neglecting friction, equally accelerating a 10-kg brick requires A) just as much force B) 10 times as much force C) 100 times as much force D) one-tenth the amount of force E) none of these
Answer: B Diff: 2
A rock is thrown vertically into the air. At the top of its path, its acceleration in meters per second per second is A) zero B) 9.8 C) between 0 and 9.8 D) greater than 9.8
Answer: B Diff: 2
An object following a straight-line path at constant speed A) has a net force acting upon it in the direction of motion B) has zero acceleration C) has no forces acting on it D) none of these
Answer: B Diff: 2
If the mass of an object does not change, a constant net force on the object produces constant A) velocity B) acceleration C) both of these D) neither of these
Answer: B Diff: 2
The maximum acceleration of a car while towing a second car twice its mass, compared to its acceleration with no car in tow, is A) one half B) one third C) one fourth D) the same E) none of these
Answer: B Diff: 2
A car traveling at 22 m/s comes to an abrupt halt in 0.1 second when it hits a tree. What is the deceleration in meters per second per second of the car? A) 110 B) 220 C) 800 D) 880 E) can't be solved without the mass of the car
Answer: B Diff: 3
If you are driving at 20 m/s and slam on your brakes and skid at 0.5 g to a full stop, the skidding time in seconds is A) about 3 B) about 4 C) about 5 D) about 6 E) more than 6
Answer: B Diff: 3
A 1-kg mass at the Earth's surface weighs A) 1N B) 4.9N C) 9.8N D) 10.8N E) none of these
Answer: C Diff: 1
A 10-N falling object encounters 4 N of air resistance. The net force on the object is A) 0N B) 4N C) 6N D) 10N E) none of these
Answer: C Diff: 1
An apple at rest weighs 1N. The net force on the apple when it is in free fall is A) 0N B) 0.1N C) 1N D) 9.8N E) none of these
Answer: C Diff: 1
An object is propelled along a straight-line path by a force. If the net force were doubled, the object's acceleration would be A) half as much B) the same C) twice as much D) four times as much E) none of these
Answer: C Diff: 1
Neglecting friction, a large block of ice and a small block of ice start sliding down an incline together. The heavier block will get to the bottom A) before the light block B) after the light block C) at the same time as the light block
Answer: C Diff: 1
The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is A) more than 10 N B) less than 10 N C) 10 N
Answer: C Diff: 1
When a woman stands at rest with both feet on a scale, it reads 500 N. When she gently lifts one foot, the scale reads A) less than 500N B) more than 500N C) 500N
Answer: C Diff: 1
A bag of groceries has a mass of 10 kilograms and a weight of A) about 1 N. B) about 10 N. C) about 100 N. D) about 1000 N. E) more than 1000 N.
Answer: C Diff: 2
A block is dragged without acceleration in a straight-line path across a level surface by a force of 6 N. What is the force of friction between the block and the surface? A) less than 6N B) more than 6N C) 6N D) need more information to say
Answer: C Diff: 2
A force of 1N accelerates a mass of 1kg at the rate of 1m/s squared. The acceleration of a mass of 2kg acted upon by a force of 2N is A) half as much B) twice as much C) the same D) none of these
Answer: C Diff: 2
A jumbo jet has a mass of 100,000 kg. The thrust for each of its four engines is 50,000 N. What is the jet's acceleration in meters per send per second when taking off? A) 0.25 B) 1 C) 2 D) 4 E) none of these
Answer: C Diff: 2
A rock is thrown vertically into the air. At the very top of its trajectory the net force on it is A) less than its weight B) more than its weight C) equal to its weight
Answer: C Diff: 2
A rocket becomes progressively easier to accelerate as it travels upward from the ground mainly because A) gravity becomes weaker with increased distance B) the applied force on the rocket increases as burning of fuel progresses C) the mass of the rocket decreases as fuel is burned
Answer: C Diff: 2
A tow truck exerts a force of 3000 N on a car, which then accelerates at 2 m/s2. What is the mass of the car? A) 500 kg B) 1000 kg C) 1500 kg D) 3000 kg E) none of these
Answer: C Diff: 2
Hang from a pair of gym rings and the upward support forces of the rings will always A) each be half your weight B) each be equal to your weight C) add up to equal your weight
Answer: C Diff: 2
Suppose a particle is being accelerated through space by a 10-N force. Suddenly the particle encounters a second force of 10 N in the opposite direction from the first force. The particle with both forces acting on it A) is brought to a rapid halt. B) decelerates gradually to a halt. C) continues at the speed it had when it encountered the second force. D) theoretically tends to accelerate toward the speed of light. E) none of these
Answer: C Diff: 2
A 1000-kg automobile enters a freeway on-ramp at 20 m/s and accelerates uniformly up to 40 m/s in a time of 10 seconds. How far does the automobile travel during that time? A) 100m B) 200m C) 300m D) 400m E) none of these
Answer: C Diff: 3
A 2000-kg car experiences a braking force of 10,000 N and skids to a stop in 6 seconds. The speed of the car just before the brakes were applied was A) 1.2 m/s B) 15 m/s C) 30 m/s D) 45 m/s E) none of these
Answer: C Diff: 3
An object released from rest on another planet requires one second to fall a distance of 6 meters. What is the acceleration in meters per second per second due to gravity on this planet? A) 3 B) 6 C) 12 D) 15 E) none of these
Answer: C Diff: 3
The human body can, under certain conditions, withstand an acceleration of 10g. What net force would produce this acceleration of a 50-kg person? A) about 500N B) about 2500N C) about 5000N D) about 25,000N E) none of these
Answer: C Diff: 3
What horizontally-applied force will accelerate a 400-kg crate at 1 m/s2 across a factory floor against a friction force half its weight? A) 600N B) 1600N C) 2000N D) 2400N E) none of these
Answer: C Diff: 3
If a non-rotating object has no acceleration, then we can say for certain that it is A) at rest B) moving at constant non-zero velocity C) in mechanical equilibrium D) all of these E) none of these
Answer: C Diff: 2
An object is propelled along a straight-line path in space by a force. If the mass of the object somehow becomes twice as much, it's acceleration A) quadruples B) doubles C) stays the same D) halves E) none of these
Answer: D Diff: 1
Which has zero acceleration? An object A) at rest B) moving at constant velocity C) in mechanical equilibrium D) all of these E) none of these
Answer: D Diff: 1
A car has a mass of 1000 kg and accelerates at 2 meters per second per second. What is the magnitude of the net force exerted on the car? A) 500N B) 1000N C) 1500N D) 2000N E) none of these
Answer: D Diff: 2
When you relax at rest with your left foot on one bathroom scale and your right foot on a similar scale, each of the scales will A) indicate exactly half your weight B) indicate part of your total weight but not necessarily half of it C) indicate different values that will equal your weight when added together D) any of the above may be correct
Answer: D Diff: 2
A 10-kilogram block with an initial velocity of 10 m/s slides 10 meters across a horizontal surface and comes to rest. It takes the block 2 seconds to stop. The stopping force acting on the block is about A) 5N B) 10N C) 25N D) 50N E) none of these
Answer: D Diff: 3
A skydiver of mass 100 kg experience air resistance of 500 N, and an acceleration of A) about 0.2g B) about 0.3g C) about 0.4g D) about 0.5g E) more than 0.5g
Answer: D Diff: 3
A 1-kg ball is thrown at 10 m/s straight upward. Neglecting air resistance, the net force that acts on the stone when it is halfway to the top of its path is about A) 1/2N B) 1N C) 5N D) 7.5N E) 10N
Answer: E Diff: 3
An astronaut on another planet drops a 1-kg rock from rest and finds that is falls a vertical distance of 25 meters in one second. On this planet, the rock has a weight of A) 1N B) 2N C) 3N D) 4N E) 5N
Answer: E Diff: 3
The brakes of a speeding truck are slammed on and it skids to a stop. If the truck were heavily loaded so that it had twice the total mass, the skidding distance would be A) 1/2 as far B) 1 1/2 times as far C) 2 times as far D) 4 times as far E) the same
Answer: E Diff: 3
