1). From the frame of reference of a passenger on the airplane looking out of his window, the tree appears to be moving, at roughly 300 miles per hour toward the left of the picture.
2). The SI unit best suited to measuring the height of a building is the meter.
3). 'Displacement' is the straight-line distance and direction from the start-point to the end-point, regardless of the path that was followed to get there.
The ball started out in the child's hand, and it ended up 2 meters away from her in the direction of the wall. So the displacement of the ball from the beginning to the end of the story is: 2 meters toward the wall.
2. Describe two ways to change the
frictional force between two solids surfaces.
Change the lubrication between the two surfaces
Change the normal force between the two surfaces
3. How does air resistance affect the
velocity of a falling object?
4. What two sources of friction do you
have to overcome when you are walking?
5. If you push a chair across the floor
at a constant velocity, how does the force of friction compare with the force
exert? Explain.
6. If you push a book against a wall
hard enough, it will not slide down even though gravity is pulling it. Use what
you know about Newton’s laws of motion to explain why the book doesn’t fall.
Answer:
A. 8.5 m/s
Explanation:
vᵧ = v sin θ
vᵧ = (20 m/s) (sin 25°)
vᵧ = 8.5 m/s
I took the test and got A) 8.5 correct
B. Matter moves at right angles to the direction of a longitudinal wave, and at right angles to the direction of a transverse wave.
C. A longitudinal wave does not need matter through which to travel, while a transverse wave does.
D. A longitudinal wave needs matter through which to travel, while a transverse wave does not.
Answer:
B
Explanation:
Transverse waves cause the medium to move perpendicular to the direction of the wave. Longitudinal waves cause the medium to move parallel to the direction of the wave.