Balance of Force
3. If a toy car is traveling in a straight line, slows down and then stops, you can conclude that a/an _______ __________ force acted on the toy car causing it to stop.
What is external unbalanced?
2. __________________ is the energy stored within an object due to its position, while ___________ is the energy of motion.
potential energy & kinetic energy.
When an object is in motion with constant speed, what does the position versus time graph look like?
It looks like a straight line with a constant slope.
When the mass of an object is doubled, the kinetic energy of the object is
doubled.
9. Which situations displays work being done? A. Johnny lifts the small container from the floor to the table B. Billy holds both containers C. Suzy is standing by the door holding the large container
A. Johnny lifts the small container from the floor to the table
4. A book on a desk does not fall off because the forces on the book are _________ and the book remains at rest.
balanced
16. Which item would have more gravitational potential energy: a book on top of a 10-foot ladder or a brick on a desk?
a book on top of a 10-foot ladder
18. If you know the speed of the object, what else do you need to know to determine its velocity?
The direction it is moving
When the velocity of an object in motion is doubled, the kinetic energy of the object is
quadrupled
zero work is done
If an object has balanced forces in the vertical direction, and it still accelerates that means the object has __________ __________ in the __________ _________________
WHat is unbalanced forces in the x direction?
17. An airplane drops a bomb from 25,000 feet. Describe what happens with the potential and kinetic energy of the bomb
As the kinetic energy increases, the potential energy decreases.
19. What does the line look like on a position-time graph when the object is accelerating (constant speed).
an exponential curve
Kinetic energy has units of Joules and _______
What is Newton-Metre?
14. Jenny oils the blades on her oscillating fan to keep it from squealing. What does the oil do the blades? A. doubles the friction B. reverses the motion C. decreases the friction D. removes all friction
C. decreases the friction
10. A mother is out for a walk with her baby in a stroller. She is exerting a forward force on the stroller. Friction between the wheels on the stroller and the sidewalk exert a backward force on the stroller. What can you conclude about the forces on the stroller as it moves forward? What Newton's law is it in effect?
C. The force of her push has a greater magnitude than the force of friction.
A simple pendulum has maximum potential energy at _____ ______ and maximum kinetic energy at the ________ _______
What is extreme position and mean position?
When a ball is thrown upwards, the velocity of the ball ________ and the acceleration of the ball ________ _________.
What is decreases and stays constant?
If the kinetic energy of an object is plotted against its velocity on a graph, the graph would have a/an _______ ________
an exponential curve.
When work is done against non-conservative force, it is given out as _______ to the surroundings.
What is heat?
When force is plotted against mass, the graph has a slope depicting the __________ of the object.
What is acceleration?
A compressed spring in a toy is used to launch a
5.00-gram ball. If the ball leaves the toy with an
initial horizontal speed of 5.00 meters per second,
the minimum amount of potential energy stored
in the compressed spring was
What is 0.0625 J?
What physical quantity is obtained when you calculate the area under the curve of a velocity- time graph?
What is displacement?
2
A constant eastward horizontal force of 70 N
is applied to a 20 -kilogram crate moving toward the
east on a level floor with a velocity of 3 m/s? How far did the crate move?
What is 1.3 m?
What physical quantity is given when you calculate the area of a Force against displacement of an object in motion graph?
What is work done?