| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.02 |
| Score | 0% | 60% |
Changes to an object's speed or direction of motion are caused by which of the following?
power |
|
a force |
|
kinetic energy |
|
work |
Force is applied to change an object's speed or direction of motion.
Veins __________ blood at __________ pressure.
deoxygenated, low |
|
deoxygenated, high |
|
oxygenated, high |
|
oxygenated, low |
Veins carry blood back to the heart from the body. While arteries are thick-walled because they carry oxygenated blood at high pressure, veins are comparatively thin-walled as they carry low-pressure deoxygenated blood. Like the heart, veins contain valves to prevent blood backflow.
The energy posessed by a ball on the window ledge of a tall building is an example of what kind of energy?
inherent |
|
potential |
|
kinetic |
|
gravitational |
Kinetic energy is the energy posessed by a moving object. Potential energy is stored energy in a stationary object based on its location, position, shape, or state.
Which of the following is not true about mass and weight?
weight is the force exerted on an object by gravity |
|
mass depends on the location where it is measured |
|
weight depends on the location where it is measured |
|
mass is the amount of matter something has |
Mass is the amount of matter something has while weight is the force exerted on an object's mass by gravity. So, although a person's mass doesn't change when going from the Earth to the Moon, their weight will decrease because the force of the Moon's gravity is much less than that of Earth.
The heart __________ blood.
deoxygenates |
|
oxygenates |
|
creates |
|
filters |
To provide oxygen to the body, blood flows through the heart in a path formed by the right atrium → right ventricle → lungs → left atrium → left ventricle → body. When blood enters the right side of the heart it is deoxygenated. It enters the left side of the heart oxygenated after traveling to the lungs.