Answer:
A: 20 km/h, B: 10 km/h
Explanation:
Speed of Vehicle A = 40-20/ 2-1
=20 km/h
If A is 20km/h, B is 10km/h as given in option
The answer to the problem is 4.5 kilometers. you can solve this problem by cross multiplying
The question is incomplete, the complete question is;
Which statement describes a difference between electromagnetic and mechanical waves?
A. Mechanical waves cannot be longitudinal, but electromagnetic waves can.
B. Electromagnetic waves cannot move particles, but mechanical waves can.
C. Electromagnetic waves do not require a medium, but mechanical waves do.
D. Mechanical waves do not transfer energy, but electromagnetic waves do.
Answer:
Electromagnetic waves do not require a medium, but mechanical waves do.
Explanation:
A wave is defined as a disturbance along a medium which transfers energy. Waves may be classified as mechanical waves or electromagnetic waves based on their medium of propagation.
A mechanical wave requires a material medium for propagation. An example of a mechanical wave is sound waves. Sound waves are propagated in air.
Electromagnetic waves do not require a material medium for propagation. They can travel through space. An example of electromagnetic waves is light waves.
Answer:
3.6 grams of NaCl are needed
Explanation:
Percent solution are solutions whose concentrations are expressed in percentages. The amount(either weight or volume) of a solute is expressed as a percentage of the total weight or volume of solution. Percent solutions can either be expressed as weight/volume % (wt/vol % or w/v %), weight/weight % (wt/wt % or w/w %), or volume/volume % (vol/vol % or v/v %).
A 6.0% wt/wt % solution contains 6 g of solute in 100 g of solution
Therefore, a 100 g solution contains 6.0 g of solute.
60 g of 6.0% solution will contain 60 g solution * 6.0 g solute/ 100 g solution
Mass of NaCl present = 3.6 g of NaCl
