Science Tests for Exam
when an object equals terminal velocity its acceleration is
0 m/s2
a ball is thrown straight upward at a speed of 10 m/s. Ideally (no air resistance) the ball will return to the throwers hand with a speed of
10 m/s
a 20N falling object encounters 4 N of air resistance. The magnitude of the net force on the object is...
16N
a girls pulls on a 10kg wagon with a force of 20N. What is the wagons acceleration
2 m/s2
suppose a small plane can fly at 170 km/h relative to the surrounding air. Suppose also that there is a 60 km/h tailwind. How fast does the plane's shadow move across the ground?
230 km/h
suppose the force of friction on a sliding object is 25N.The force needed to maintain a constant velocity is
25 N
when a woman stands with two feet on a scale, the scale reads 280. When she lifts one foot, the scale reads...
280 N
In the absence of air resistance the angle at which a thrown ball will go the furthest is
45 degrees
what is the resultant of a 3-unit vector and a 4-unit at right angles to each other?
5 units
forces always occur in pairs a 660 N woman sits on the floor, the floor exerts of force on her of...
600N
a cannonball is launched horizontally from a tower. If the cannon has a barrel velocity of 60 m/s, when will the cannonball be one second later?
60m downrange
how much force is needed to accelerate a 4.0 kg physics book to an acceleration of 2.0 m/s
8.0 N
a bag of sports equitment has a mass of 10.0 kg and a weight of...
98 N
A scientist who would have most likely studied with plato is
Aristotle
this scientist was placed under house arrest because he refused to take back the ideas he had published against the church
Galileo
in the absence of air friction, the horizontal component of a projectiles velocity doesn't change as the projectile moves.
always true
At what part of the path does the projectile have minimum speed?
at the top of its path
the law of inertia applies to
both moving and non-moving objects
suppose a particle is accelerated through space by a constant 10 N force, Suddenly the particle encounters a second force of 10 N in a direction opposite than that first force. The particle
continues at the speed it has when encountered by the second force
when the angle of an incline with a block resting on it increases, the normal support force..
decreases
accelerations are produced by
forces
Galileo performed many experiments studying the force of
friction
an object is dropped and falls freely to the ground with an acceleration of g. if it is thrown upward at an angle instead its acceleration would be
g downword
an object following a straight line path at constant speed
has a net force of acting on it in the direction of motion
an object following in a straight line path at constant speed
has zero acceleration
the momentum change of an object is equal to the
impulse acting on it
in order to increase the final momentum of a golf ball, we could
increase the force acting on, follow through when hitting the ball, increase the time of contact with the ball and swing as hard as possible
the reason padded dashboards are used in cars is that
increase the time of impact in a collision
the object has twice as much mass as another object. The first object also has twice as much
inertia
how does acceleration of an object change in relation to its mass? it is....
inversely proportional
a projectile is fired horizontally in a vacuum. The projectile maintains its horizontal component of speed because it...
is not acted on by any horizontal forces
if the force acting on a cart doubles, what happens to the carts acceleration?
it doubles
suppose a cart is being moved by a force. If suddenly a load is dumped into the cart so that the cart's mass doubles, what happens to the cart's acceleration?
it halves
if the momentum of an object changes and its mass remains constant
it is accelerating or decelerating, there is a force acting on it and its velocity is changing
A vector is a quantity that has
magnitude and direction
the momentum of an object is defined as the object's
mass times its velocity
which has more mass, a kilogram of feathers or a kilogram of iron?
neither they both have the same mass
friction is a force that always acts
oposite to an objects motion
Isaac Newton studied
physics, theology and alchemy
The astronomer copernicus publicly stated in the 1500's that earth
revolves around the sun
The weight of a person can be represented by a vector that acts
straight down even if the person is standing on a hill
which has more momentum, a large truck moving at 30 mph or small truck moving at 30 mph
the large truck
a sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. the reason this can be done is
the milk carton has inertia
you would have the largest mass of gold weighed 1N on
the moon
A major publication by Isaac Newton was
the principia
A force of 3N accelerates a mass of 3kg at the rate of 1 m/s2. the acceleration of a mass of 6 kg acted upon by a force of 6 N is...
the same
a table tennis ball launcher is fired. Compared to the impulse on the ball, the impulse on the launcher is...
the same
compared to its mass on earth the mass of a 10kg object on the moon is...
the same
after a rock is thrown straight up reaches the top of its path and is starting to fall back down, its acceleration is (neglecting air resistance)
the same as when it was at the top of its path
the horizontal component of a projectiles velocity is independent of
the vertical component of its velocity
a collision is considered elastic if
there is no lasting deformation, the objects stick together, the objects that collide don't get warmer and after the collision the objects have the same shape as before the collisions
compared to a sports car moving at 60 mph vs the same sports car moving at 30 mph has
twice as much momentum
after a cannonball is fired into a fritionless space, the amount of force needed to keep it going equals
zero, since no force is needed to keep it moving