ALL🌑 Flashcards
(38 cards)
At the Instant a ball is Thrown horizontally with a large force, an identical ball is dropped from the same height. which ball hits the ground faster?
Neither.they both hit the ground at the same time
A ball is thrown into the air at some angle.at the very top of the balls path it’s velocity is…
Entirely horizontal
In the absence of air assistance The angle at which a thrown ball will go the farthest is
45 degrees
A cannonball is launched from the ground at an angle of 30° above the horizontal and a speed of 30 m/s.ideally (no air resistance) the ball will land on the ground with the speed of
30 m/s
A project launched horizontally hits the ground in .8 seconds .if It had been launched with a much higher speed in the same direction it would have hit the ground in
.8s
An object is dropped and falls freely to the ground with an acceleration of g. If it is thrown upward at an angle instead, it’s acceleration would be
G downward
A baseball is hurled into the air at an angle of 30° above the horizontal and lands on the target that is at the same level as that where the baseball started.The baseball will also land on the target if it is thrown at an angle of
60 degrees
“Hang time “is the time a jumper’s feet or off the ground in a vertical jump.if the jumper runs and has the same vertical component of take off velocity hang time will be
No different
A cannonball is fired at some angled into the air .in the first second it moves 5 m horizontally.how far does it move horizontally in the next second
5m
Supposed the force of friction on a sliding object is 25N. The force needed to maintain a constant velocity is
25N
A box is dragged without acceleration in a straight line path across a level surface by a force of 13N. What is the frictional force between the box and the surface
13N
If the force acting on a cart doubles what happens to the cart’s 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
A 20N falling object encounters 4N of air resistance. The magnitude of the net force on the object is
16N
A Jumbo Jet cruises at a constant velocity when the total thrust of the engines on the jet is 50,000N.how much air resistance acts on the jet
50,000N
Compared to a sports car moving at 30 mph the same sports car moving at 60 mph has
Twice as much momentum
If the momentum of an object changes and it’s mass remains constant
A it is accelerating B there is a force acting on it C it's velocity is changing D all of the above E none of the above
Answer : d all of the above
In order to increase the final momentum of a golf ball we could
A increase the force acting on it B follow through when hitting the ball C increase the time of contact with the ball D swing as hard as possible E all of the above
Answer: e all of the above
Momentum of a system is conserved only when
There is no net external force acting on the system
It collision is considered elastic if
A there is no lasting deformation
B the objects don’t stick together
C after the collision the object has the same shape as before the collision
D all of the above
Answer: d all of the above
A freight train Rolls along a track with considerable momentum. If it were to roll at the same speed but had twice as much mass its momentum would be
Doubled
A Canon recoils from launching a cannonball.The speed of the cannons recoil is small because the
Canon has four more mass than the cannonball
Two objects ,A and B ,have the same size and shape but A is twice as heavy as B. when they are dropped simultaneously from a tower they which the ground at the same time but A has a higher
Momentum
A moving freight car runs into an identical car at rest on the track. The cars couple together compared to the velocity of the first car before the collusion the velocity of the combine cars after the collision is
One half as large
