IndietroPhysics chapter 5 dynamic study module
Termini in questo insieme (27)
Imagine standing in an elevator that is moving upward. Which of the following is the most complete list of the forces that belong on your free-body diagram (FBD) in that moment?
The normal force on you by the elevator floor and the force of gravity on you by the earth
In a tug-of-war contest, what determines the winner?
Whichever team pushes on the ground with more force
A person is standing still while leaning against the wall in a classroom. Which is the best answer regarding the number of forces exerted on her?
At least four
The force of the surface that acts on an object perpendicular to the surface is known as the __________.
normal force
As you accelerate upward in an elevator, which force exerted on you has the greatest magnitude?
The normal force from the elevator floor pushing up on you
Josh punches his open left hand with his right hand. Which statement is true about the forces his two hands exert on each other?
Josh’s right hand and left hand exert equal and opposite forces on each other.
Newton's Third Law is commonly referred to as __________.
action-reaction
Michael leans on a shopping cart, causing it to start moving. Which statement is true about the forces Michael and the cart exert on each other?
Michael and the cart exert equal and opposite forces on each other.
Tires pushing the road backward, the road pushing the car forward
Newton's Third Law
A tablecloth being quickly pulled away, leaving the place settings at rest
Newton's First Law
A shopping cart getting harder to push as it fills up with groceries
Newton's Second Law
Which of the following is a legitimate way to describe the force between a road and a car driving on the road?
The normal force exerted by the road on the car
A box rests on a table. The normal force exerted by the table on the box is equal in magnitude to the weight of the box and points in the opposite direction. This is because __________.
the net force on the box is zero and, therefore, the forces must be balanced
The upward reaction force on the blades of a helicopter is called the __________.
lift force
Consider a car speeding up as it drives along a level road. Which of the following is an action-reaction pair (from Newton’s third law)?
The normal force exerted on the car by the road and the downward force exerted on the road by the car.
Consider a car driving at a constant speed on a level road. Which of the following is an action-reaction pair (from Newton’s third law)?
The normal force exerted on the car by the road and the downward force exerted on the road by the car.
Miguel leans against a wall. Which statement is true about the forces Miguel and the wall exert on each other?
Miguel and the wall exert equal and opposite forces on each other.
In which case would the normal force acting on a 200 N boy be the greatest?
When the boy is standing on a flat surface
While sparring, Katie punches Arman in the shoulder. Which statement is true about the forces Katie and Arman exert on each other?
Katie exerts a force on Arman’s shoulder and Arman exerts a force on Katie’s hand.
Floating in deep space, you find yourself at rest next to a small asteroid. You reach out and tap the asteroid with a hammer. What happens to you in this process?
You will briefly accelerate away from the asteroid and then drift away at a constant speed.
Allison pulls her little brother, Brody, in a sled on a snow-covered path at a constant speed. Which of the following is an action-reaction pair (from Newton’s third law)?
The pulling force that Allison exerts on the sled and the pulling force that the sled exerts on Allison.
Jack and Luis are pushing on opposite ends of a shopping cart. At the moment, the cart is staying at rest. We know that the forces each person exerts on the cart are equal in magnitude and opposite in direction. What is the reason this must be true?
Newton’s second law tells us these two forces must be equal and opposite.
An object rests on a ramp that is angled at 20º above the horizontal. What direction (relative to the vertical) will the normal force from the ramp point?
The normal force will be directed 20º to the right of vertical.
To define the position of an object in a plane, you need to measure __________.
the object’s distance from a reference point and its angle measured from a reference line
Imagine a car sitting empty in the parking lot. Which of the following is the most complete list of the forces that belong on a free-body diagram (FBD) of the car?
The normal force on your car by the pavement it rests on and the force of gravity on your car by the earth
An object rests on a ramp that is angled at 20º above the horizontal. What direction (relative to the vertical) will the force of gravity point?
The gravitational force will be directed exactly downward, along the vertical.
Which of the following statements is true?
The Earth and Moon attract one another with a force of equal magnitude.