Physics conceptual tests 4-5
Considering Newton's 3rd law of motion, if the action force s tennis racket pushes on a ball, then the reaction force is...
ball pushes on racket with equal and opposite force
A pilot drops a package from a plane flying horizontally at a constant speed. Neglecting air resistance, when the package hits the ground the horizontal location of the plane will...
be directly over package, package doesn't stop having Vx.
Which type of force is the support force exerted upon an object that is in contact with another stable object?
normal force
All vectors have two components which are called...
opposite and adjacent
What effect does lifting up on a heavy box have to the box to make it seem easier to move?
reduces the normal force
For general projectile motion with no air resistance, the horizontal component of a projectile's acceleration...
remains -9.81 m/s/s
For general projectile motion with no air resistance, the horizontal component of a projectile's velocity...
remains a non-zero constant
Which of the following is not vector quantity? velocity displacement speed acceleration
speed
What is the greatest kind of friction?
static friction
A 75 N box rests on a frictionless horizontal surface. The minimum force needed to start the box moving in a horizontal direction is...
Any horizontal force greater than zero
Jon and his sister Katie are both standing on identical skateboards (with really good frictionless ball bearings), initially at rest. Jon weighs two times as much as Katie. Jon pushes horizontally on Katie's back, causing Katie to start moving away from Jon. Just after Jon stops pushing,...
Katie and Jon are moving away from each other, and Katie's speed is two times that of Jon.
Which law of motion relates unbalanced force and mass to acceleration (F=ma)
Newton's 2nd law
Which law of motion states that an object at rest remains at rest and object in motion remain at a constant velocity unless acted on by an unbalanced force?
Newton's first law
The acceleration due to gravity is lower on the Moon than on Earth. What is true about the mass and weight of an astronaut on the Moon's surface, compared to Earth?
Same mass, different weight
A ball is thrown horizontally from the top of a tower t the same instant that a stone is dropped vertically. Which object is traveling faster when it hits the level ground below if neither of them experience any air resistance?
The ball because it has velocity and acceleration, the stone only has acceleration.
How will the motion of a ball rolling on the ground change if the ball encounters more friction?
The object will slow down at a greater rate because of the additional unbalanced force.
You are standing in a moving bus, facing forward, when you suddenly slide forward as the bus comes to an immediate stop. What force caused you to slide forward?
There is not a force causing you to slide forward, it is your inertia
In an air-free chamber, a pebble is thrown horizontally, and at the same instant a second pebble is dropped from the same height. Compare the times of fall of the two pebbles.
They hit the ground at the same time.
What is the cause of an acceleration?
an unbalanced force
What are the two ways of determining the net force on an object?
free body diagram and F=ma
A bucket is being lowered by a very light rope with a constant downward velocity he tension in the rope must be...
has to be equal because it's in equilibrium
Whenever you are adding vectors, what is drawn from the tail of the first to the tip of the last?
hypotenuse
What is the tendency of an object to maintain its state of motion?
inertia
An object is moving with constant non-zero velocity. What statement about it must be true?
the net force on the object is zero