Physics 250 Test Questions and All
Correct Answers.
Normal force acts on an object when - Answer That object is on a surface (not one hanging
in air)
To find tension of hanging block... - Answer Make separate formula for both blocks
Newton's Second Law - Answer Force = mass x acceleration
Newton's First Law - Answer an object at rest will stay at rest, an object that is moving will
stay moving unless disturbed by an un balenced force.
Newton's Third Law - Answer For every action there is an equal and opposite reaction
Solve step 1 - Answer Free force diagram
Solve step 2 - Answer Write out eqation... may need Fx and Fy
Two athletes run in different directions at 10 mph. One heads east and one goes south. Are
their speeds the same? - Answer Yes; looking at distances traveled in period of time
Two athletes run in different directions at 10 mph. One heads east and one goes south. Are
their velocities the same? - Answer No; they are headed in different directions- velocity is
the speed of an object in a given direction
can a car that has only been traveling at different speeds in a straight line east have accelerated
north? - Answer No because it is only changing in speed not magnitude - no motion or force
to push it another direction
Can a car that has been traveling at different speeds in a straight line east have accelerated
west? - Answer Yes! If it has a negative speed (backing up) the car can move west
If the tops of two chains vertically supporting a chandelier are separated (no longer vertical),
does the tension increase or decrease? - Answer it will increase
Each tension will break into two components. Horizontal components will cancel out as both are
in the opposite direction. Vertical components will add, as both are in the same direction.
, When the external force on an object exceeds the maximum force, the object... - Answer
starts moving
What is static friction? - Answer the force that resists the initiation of sliding motion
between two surfaces that are in contact and at rest
What is kinetic friction? - Answer Friction that exist when a larger amount of force is exerted
and one object does move.
What are projectiles? - Answer Objects that are launched into the air(motion affected by
gravity)
In a projectile, horizontal and vertical motions are _______________________ - Answer
independent of one another
Launching a projectile at which angle will make the projectile travel the greatest horizontal
distance? Assume no friction and that the initial velocity is the same for each angle. - Answer
45 degrees --> compromise between long time flight and large horizontal velocity
t = (2Vi sin (angle))/g
x = (Vi^2 sin (2 x angle)) / g
Consider a box sitting in the back of a pickup truck that accelerates toward the right. Because
the bed of the pickup is rough, the box does not slide. What are the directions of the forces that
the truck exerts on the box? - Answer upward and right
Consider a box sitting in the back of a pickup truck that accelerates toward the right. Because
the bed of the pickup is rough, the box does not slide. Identify forces acting on the box - Answer
gravitational, normal, static friction
a box rests on a horizontal surface. you apply a force on the box of F = 100 N at an angle below
the horizontal, and it slides at a constant velocity. the friction force that acts on the box is? -
Answer less than 100 N
The wheels of a midsize car exert a force of 2350 N backward on the road to accelerate the car
in the forward direction. The force of friction including air resistance is 250 N and the
acceleration of the car is 1.65 m/s2. What is the mass? - Answer F-Fr = m*a
m = 1272.7
Correct Answers.
Normal force acts on an object when - Answer That object is on a surface (not one hanging
in air)
To find tension of hanging block... - Answer Make separate formula for both blocks
Newton's Second Law - Answer Force = mass x acceleration
Newton's First Law - Answer an object at rest will stay at rest, an object that is moving will
stay moving unless disturbed by an un balenced force.
Newton's Third Law - Answer For every action there is an equal and opposite reaction
Solve step 1 - Answer Free force diagram
Solve step 2 - Answer Write out eqation... may need Fx and Fy
Two athletes run in different directions at 10 mph. One heads east and one goes south. Are
their speeds the same? - Answer Yes; looking at distances traveled in period of time
Two athletes run in different directions at 10 mph. One heads east and one goes south. Are
their velocities the same? - Answer No; they are headed in different directions- velocity is
the speed of an object in a given direction
can a car that has only been traveling at different speeds in a straight line east have accelerated
north? - Answer No because it is only changing in speed not magnitude - no motion or force
to push it another direction
Can a car that has been traveling at different speeds in a straight line east have accelerated
west? - Answer Yes! If it has a negative speed (backing up) the car can move west
If the tops of two chains vertically supporting a chandelier are separated (no longer vertical),
does the tension increase or decrease? - Answer it will increase
Each tension will break into two components. Horizontal components will cancel out as both are
in the opposite direction. Vertical components will add, as both are in the same direction.
, When the external force on an object exceeds the maximum force, the object... - Answer
starts moving
What is static friction? - Answer the force that resists the initiation of sliding motion
between two surfaces that are in contact and at rest
What is kinetic friction? - Answer Friction that exist when a larger amount of force is exerted
and one object does move.
What are projectiles? - Answer Objects that are launched into the air(motion affected by
gravity)
In a projectile, horizontal and vertical motions are _______________________ - Answer
independent of one another
Launching a projectile at which angle will make the projectile travel the greatest horizontal
distance? Assume no friction and that the initial velocity is the same for each angle. - Answer
45 degrees --> compromise between long time flight and large horizontal velocity
t = (2Vi sin (angle))/g
x = (Vi^2 sin (2 x angle)) / g
Consider a box sitting in the back of a pickup truck that accelerates toward the right. Because
the bed of the pickup is rough, the box does not slide. What are the directions of the forces that
the truck exerts on the box? - Answer upward and right
Consider a box sitting in the back of a pickup truck that accelerates toward the right. Because
the bed of the pickup is rough, the box does not slide. Identify forces acting on the box - Answer
gravitational, normal, static friction
a box rests on a horizontal surface. you apply a force on the box of F = 100 N at an angle below
the horizontal, and it slides at a constant velocity. the friction force that acts on the box is? -
Answer less than 100 N
The wheels of a midsize car exert a force of 2350 N backward on the road to accelerate the car
in the forward direction. The force of friction including air resistance is 250 N and the
acceleration of the car is 1.65 m/s2. What is the mass? - Answer F-Fr = m*a
m = 1272.7
