43 terms

Physics short answer

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Explain how a dog that has moved can have a displacement of zero
The dogs initial position and final position are the same
Construct a graph of position versus time for the motion of the dog using data in the table above. What is the dogs average velocity?
1/2 m/s
How can you determine the instantaneous velocity at a given point on a position versus time graph
Calculate the slope of a line drawn tangent to the point in question
A motorized scooter starts from rest and accelerates for 4 s at 2m/s^2. It continues at a constant speed for 6 s graph the scooters velocity versus time. Explain how you could use the graph to show that the scooters acceleration is constant during the intervals 1-2 s and 5-6 s.
The scooters acceleration is constant for both intervals because the velocity versus time graph is a straight line for both
Two rocks are dropped simultaneously and undergo free fall. Compare their displacements after equal intervals of time
The displacements are equal
In the situation above the velocity of the crew member with respect to the tugboat is v1. What is the velocity of the crew member with respect to the barge?
V1
In the situation above the captain records the upstream speed of the tug boat relative to the river. A dockhand records the tugboats upstream speed relative to the shore.how do the recorded speeds differ?
The tug boats speed relative to the river will be faster then relative to the shore
In the situation above what is at rest relative to the tug boat
The barge
In the figure above what would happen to the width of the balls path of it were launched with a greater velocity?
The width of the balls path would increase
In the figure above what would happen to the height of the balls path of it were launched with a lesser velocity
The height of the balls path would decrease
List the steps in the scientific method
1. Make observations and collect data to ask a question
2. Formulate and objectively test your hypothesis by experiment
3.interpret the results and revise hypothesis if necessary
4. State conclusions and write findings in a way so others can interpret them
What are the SI unit for length mass and time
Length-meter mass-kilogram time-second
How am only seven basic units serve to express almost any measured quantity
The base units can be combined to form derived units for other quantities
What is the symbol for decimeter
dm
Accuracy
How close a measurement is to the correct value
Precision
Degree of exactness of a measurement
How can method error be minimized
By standardizing the method of taking measurements
How many sig figs does 0.050200 mg have
5
Hypothesis
Graphs often permit scientists to make these when there is no data
What Greek letter is used to mean sum or total
Sigma
What must quantities have before they an be added or subtracted
The same base unit
How does the theory of field forces explain how objects could exert forces on each other without touching
Objects exert forces on each other when there fields interact
What happens to an object in motion when it experiences a nonzero net force
The object accelerates
When an object is in equilibrium the net force is
Zero
Why does it require much less force to accelerate a low mass object than it does to accelerate a high mass object the same amount
An object with smaller mass has less inertia then an object with more mass
When a horse pulls on a cart the cart pulls on the horse with an equal but opposite force. How is the horse able to pull the cart
The horse and the cart are not necessarily in equilibrium the forces in the action reaction pair are both applied to different objects
Mass
The amount of matter in an object
Weight
The measure of the gravitational pull of an object
In what direction does the force of air resistance act
Air resistance acts in the opposite direction of an objects motion
What happens to air resistance whe an object accelerates
Air resistance increases with increasing speed
When a falling object reaches terminal speed what is the relationship between force of air resistance and force of gravity
They are equal in magnitude but opposite in direction
How does the coefficient for static friction compare to that of kinetic friction for the same surface
The coefficient of static friction is greater
Are any forces doing work on the car explain your answer
Yes the force of the engine and force of friction are doing work on the car
The cars engine is doing work on the car yet the kinetic energy of the car is not changing what is happening to the energy supplies by the engine
Energy from the engine is equal to the amount of frictional forces
What form of energy is stored in any stretched or compressed object
Elastic potential energy
Negative work is done on a moving object how does the kinetic energy of the object change
The kinetic energy will decrease
Describe the relationship between kinetic energy and gravitational potential energy during the free fall of a pencil from the desk
At the top it is all gpe and as it falls kinetic energy goes up as the gpe goes down
You are analyzing the flight of a projectile through the air what assumption do you have to make in order to use the law of conservation of mechanical energy
No frictional forces
A pendulum is raised to 1.5 cm and allowed to fall of air resistance is negligible how high will the pendulum rise on the other side
1.5 cm
Explain how energy time and power are related
Power is the transfer of energy in a time interval
How are work and power related
Power is the rate of work
What does the wattage of a light bulb indicate
The wattage tells the rate at which energy is converted by the bulb
Which motor performs more work in the same amount of time a 10 kW or a 20 kW
The 20 kW motor does twice the work in the same time