Velocity+Speed
What are the units for velocity?
Meters/Seconds (m/s) AND Direction
What is the equation for acceleration?
a= v(final) - v(initial) over time
or
a= delta v over time
A car travels 30 meter east in 2 seconds. The displacement of the car at the end of this 2 second interval is
30 meters east
An object starts from rest and falls freely. What is the speed of the object at the end of 3.00 seconds?
9.8 x 3 = 29.4 m/s
What variable represents speed?
V
Whats the difference between speed and velocity?
Speed is a scalar quantity and velocity is vector quantity
An object that is originally moving at a speed of 20 meters per second uniformly for 5. seconds to a final speed of 50 meters per second. What is the acceleration of the object?
6.0 m/s^2
The time rate of change of displacement is
velocity
Which graph best represents the motion of an object that has no unbalanced force action on it?
a) Acceleration/Time
b) Momentum/Time
c) Velocity/Time
d) Displacement/Time
d) Displacement/Time
What is the acceleration due to gravity on Earth?
9.8 m/s2
What is the average velocity of a car that travels 50 kilometers due north in 0.25 hour?
200km/hr north
The final velocity for an object will be greater than the initial velocity if an object is
speeding up/accelerating
Yaritza travels 0.14 meters north, 27 meters east, and 123 meter south. What is the total distance she traveled?
150.14 meters
Supposing you were in space in a weightless environment, would it require a force to set an object in motion? Why?
Yes, Even in space objects have mass. And if they have mass, they have inertia. That is, an object in space resists changes in its state of motion. A force must be applied to set a stationary object in motion
The formula required to solve for acceleration with a given final velocity of 20 m/s East and 5 seconds passed starting from rest is
acceleration=Change in velocity/time
a=delta v/t
A child riding a bicycle at 10 meters per second decelerates (slows down) at a rate of 2m/s^2 for 5 seconds. What is the child's speed at the end of 5 seconds?
0m/s
An object has a constant acceleration of 4.0 meters per second squared. The time required for the object to accelerate from 6 meters per second to 46 meters per second is
10s
An object initially traveling at 20 meters per second west accelerates uniformly at 4.0 meters per second^2 east for 2.0 seconds. The displacement of the object during these 2.0 seconds is
32m West
Fred spends most Sunday afternoons at rest on the sofa, watching pro football games and consuming large quantities of food. What affect (if any) does this practice have upon his inertia? Explain.
Fred's inertia will increase!
Fred will increase his mass if he makes a habit of this. And if his mass increases, then his inertia increases
What formula must be used to find a resultant vector from two perpendicular vectors given? What letter represents the resultant vector in the formula?
Pythagorean theorem a2+b2=c2
c represents the resultant
A motorboat traveling 3m/s, East encounters a current traveling 2.0 m/s North. If the width of the river is 60 meters wide, then how much time does it take the boat to travel shore to shore
20 seconds
The velocity of a car changes from 60 meters per second north to 45 meters per second north in 5.0 seconds. The magnitude of the car's acceleration is
3.0 m/s^2
A student is riding his bike to school, the student travels 2.40 kilometers west, 0.35 kilometers south, and 0.65 kilometer east. It usually takes the students 15 minutes to go home, calculate the students average speed for the entire trip.
0.226 km/mim or 0.23 km/min
Two bricks are resting on edge of the lab table. Shirley Sheshort stands on her toes and spots the two bricks. She acquires an intense desire to know which of the two bricks are most massive. Since Shirley is vertically challenged, she is unable to reach high enough and lift the bricks; she can however reach high enough to give the bricks a push. Discuss how the process of pushing the bricks will allow Shirley to determine which of the two bricks is most massive. What difference will Shirley observe and how can this observation lead to the necessary conclusion?
She will observe that the brick with the most mass will have the most inertia, meaning it is harder to move from rest, and vice versa.
What formula can be used to find the direction of the angle for the resultant vector if given two perpendicular vectors and their magnitudes?
Theta (0)=tan-1(a/b)