Please check my answers, and i'm unsure of the third problem so if you can please explain.
Which statement about friction is true?
Static friction and kinetic friction in a system always act in the same direction as each other and in the opposite direction of the applied force.
Static friction and kinetic friction in a system always act in opposite directions of each other and in the opposite direction of the applied force.****
Static friction and kinetic friction in a system always act in opposite directions of each other and in the same direction as the applied force.
Static friction and kinetic friction in a system always act in the same direction as each other and in the same direction as the applied force.
_________________________________________________________________
A brick is resting on a smooth wooden board that is at a 30° angle. What is one way to overcome the static friction that is holding the brick in place?(1 point)
lower the board so it's level with the ground
roughen up the texture of the wooden board
raise the board to a higher angle****
press down on the brick in a direction that is perpendicular to the board
_________________________________________________________________
A student uses a spring scale attached to a textbook to compare the static and kinetic friction between the textbook and the top of a lab table. If the scale measures 1,580 g while the student is pulling the sliding book along the table, which reading on the scale could have been possible at the moment the student overcame the static friction?(1 point)
1,860 g
1,140 g
1,580 g
820 g******
_________________________________________________________________
In which example is kinetic friction most involved?(1 point)
a sled stuck on a snowy hill
a bottle of water wedged in a vending machine
an explorer unsuccessfully pushing on a massive stone that is blocking the entrance to a cave
a volleyball player sliding across the court while diving for the ball*******
all are correct except its 1860 g and not 860 g
Your answers for the first question, second question, and fourth question are correct.
For the third question, the correct answer is 820 g.
To understand how to arrive at this answer, we need to understand the concept of static friction. Static friction is the force that prevents an object from moving when a force is applied to it. It is the force that acts in the opposite direction of the applied force until the force of the applied force is greater than the maximum static friction, causing the object to start moving.
In the given scenario, the student is pulling the sliding book along the table. The scale measures 1,580 g (the weight of the textbook) while the student is pulling. This reading represents the maximum static friction. When the student overcomes the static friction, the book starts moving with kinetic friction, which is typically less than static friction.
Since the scale reading is the maximum static friction, we can conclude that the maximum static friction is 1,580 g. So, the scale reading at the moment the student overcame the static friction could be any value less than 1,580 g. Among the given options, the only value less than 1,580 g is 820 g. Therefore, the reading on the scale that could have been possible at the moment the student overcame the static friction is 820 g.