Answer:
a) 16 N
b) 2.13 m/s²
Explanation:
Draw a free body diagram of the tv stand. There are four forces:
Weight force mg pulling down,
Normal force N pushing up,
Friction force Nμ pushing left,
and applied force P pulling right.
Sum of forces in the y direction:
∑F = ma
N − mg = 0
N = mg
The net force in the x direction is:
∑F = P − Nμ
∑F = P − mgμ
∑F = 25 N − (7.5 kg) (10 m/s²) (0.12)
∑F = 16 N
Net force equals mass times acceleration:
∑F = ma
16 N = (7.5 kg) a
a = 2.13 m/s²
Test:
Performing a Litmus Test
Result:
Litmus paper gives the user a general indication of acidity or alkalinity as it correlates to the shade of red or blue that the paper turns.
- To test the pH of a substance, dip a strip of litmus paper into the solution or use a dropper or pipette to drip a small amount of solution onto the litmus paper.
- Blue litmus paper can indicate an acid with a pH between 4 and 5 or lower.
- Red litmus paper can show a base with a pH greater than 8.
- If a solution has a pH between 5 and 8, it will show little color change on the litmus paper.
- A base tested with blue litmus paper will not show any color change, nor will an acid tested with red litmus paper register a change in color.
Acceleration = (change in speed) / (time for the change)
= (49 m/s) / (5 seconds)
= (49 / 5) m/s / s
= 9.8 m/s²
All ions are atoms with a charge
Engineers have designed experimental cars that use liquid hydrogen for fuel instead of gasoline. this is an example of Substitution.
Substitution is the process where one thing replaces other for a particular purpose. here liquid hydrogen is replacing the gasoline for fuel in car. hence the correct word to fill is Substitution.
