| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.14 |
| Score | 0% | 63% |
Work is measured in:
joules or newton-meters |
|
amps |
|
watts |
|
horsepower |
Work is performed on an object when an applied force causes displacement along the same vector. Measured in joules (J) or newton-meters (Nm), work is calculated by multiplying force times displacement: \(W = \vec{F}\vec{d}\)
The formula \(\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}\) applies to which of Newton's laws?
second law of motion |
|
third law of motion |
|
first law of motion |
|
universal gravitation |
Newton's law of universal gravitation defines gravity: All objects in the universe attract each other with an equal force that varies directly as a product of their masses, and inversely as a square of their distance from each other. Expressed as a formula: \(\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}\) where r is the distance between the two objects and G is the gravitational constant with a value of 6.67 x 10-11.
Convert 0C° to F°.
0 |
|
32 |
|
16 |
|
-32 |
To convert from C° to F° use:
\(F° = {9 \over 5}C° + 32\)
\(F° = {9 \over 5}(0) + 32\)
\(F° = 0 + 32 = 32\)
Acceleration is the rate of change of velocity per unit of time. Which of these is the formula for acceleration?
\(\vec{a} = { \Delta \vec{v} \over t }\) |
|
\(\vec{a} = { t \over \Delta \vec{v} }\) |
|
\(\vec{a} = { \vec{v} \over t }\) |
|
\(\vec{a} = \Delta \vec{v} t \) |
Acceleration is the rate of change of velocity per unit of time. In physics, the delta symbol (\(\Delta\)) represents change so the formula for acceleration becomes \(\vec{a} = { \Delta \vec{v} \over t }\)
Which of the following substances gives up negatively charged hydroxide ions (OH-) when dissolved in water?
hydrogen |
|
acid |
|
ion |
|
base |
An acid is a substance that gives up positively charged hydrogen ions (H+) when dissolved in water. A base (alkaline) gives up negatively charged hydroxide ions (OH-) when dissolved in water. pH is a scale that measures of how basic or acidic a solution is. Numbered from 0 to 14, solutions with a pH of 7 are neutral, less than 7 are acidic, more than 7 are alkaline.