I'm assuming the question is what is the robin's speed relative to to the ground...
Create an equation that describes its relative motion.
rVg = rVa + aVg
Substitute values.
rVg = 12 m/s [N] + 6.8 m/s [E]
Use vector addition.
| rVg | = √ | rVa |² + | aVg |²
| rVg | = √ 144 m²/s² + 46.24 m²/s²
| rVg | = √ 19<u>0</u>.24 m²/s²
| rVg | = 1<u>3</u>.78 m/s
Find direction.
tanФ = aVg / rVa
tanФ = 6.8 m/s / 12 m/s
Ф = 29°
Therefore, the velocity of the robin relative to the ground is 14 m/s [N29°E]
Answer: Teeth is an example of a wedge.
Explanation :
the machines that make our work easier are called simple machines. Some machines can be compound because they are a combination of more than two simple machines. For example, stapler.
Teeth are an example of a wedge. It is a simple machine which consists of two inclined planes. It is used to split apart objects.
The mechanical advantage of a wedge is more than 1.
So, the correct option is (b) " Wedge".