1D Motion
The rate at which an object changes its velocity.
What is acceleration
A man is whirling a 0.5 kg ball on a 1.0 m long string at 2 m/s. What is true about the force on the ball?
It pulls in, toward the center of the circle
For a projectile, which velocity remains constant as long as air resistance is ignored?
Constant velocity in horizontal direction.
Formula for calculating impulse
I=Ft
Calculate the kinetic energy of a 5.2 moving at 2.4m/s
13.1J
Displacement is a vector quantity because it includes information about:
Magnitude and Direction
Kids were playing with balls which are of equal mass. They kicked them with different forces. Which one accelerated more? Red ball – 10N, Blue ball – 3N, Yellow ball - 5N
Red ball since force and acceleration are directly related.
A football was kicked toward the goal. The horizontal component of velocity was 10 m/s and the vertical component was 7 m/s . What is the magnitude of the resultant velocity of the soccer ball?
12 m/s
What is an object's change in momentum equal to?
The impulse acting on the object
If an object is at rest, it certainly does not possess this form of energy
Kinetic Energy
An object moving backwards
Negative displacement
A child riding a merry-go-round feels a centripetal force. How would the magnitude of the acceleration change if the velocity doubled (2x)?
Decrease to one quarter (¼ x)
Consider a ball thrown up from the surface of tl1e earth into the air at an angle of 30° above the horizontal. Air friction is negligible. Just after the ball is released, its acceleration is:
Downwards at 9.8 m/s2
A layer of padding is added to car dashboards because it can reduce some injuries during a collision. How does the padded dashboard make people safer?
It increases the time of impact during the collision
Depends upon object mass and object height
Physical Energy
The rate of change in position of an object over time related to how fast an object is moving
What is velocity?
The affect of net force and mass upon the acceleration of an object. a = Fnet/m
Newtons Second Law
Any quantity that has magnitude and direction, such as displacement or velocity
What is a Vector Quantity
A stunt person jumps from the roof of a tall building, but no injury occurs because the person lands on a large, air-filled bag. Which one of the following BEST describes why no injury occurs?
The bag provides an impulse equal to the person's change in momentum by increasing the time of impact.
The sum of physical Energy and Kinetic Energy
Mechanical Energy
A graph which shows the position of and object over time.
A position time graph
For every action there is an equal and opposite reaction
Newtons Third Law
A physical quantity that is completely described by its magnitude.
What is a Scalar quantity
Egg A is dropped from a height of 1m onto the floor. Egg B is dropped from a height of 1m into a bucket of water. Which statement correctly describes why Egg B does not break?
Egg B experiences less force over a longer time
Name of a singular unit of energy.
Joule