The vertical force exerted on the lawn is 68.8 N downward
Explanation:
The vertical force exerted by the lawnmower on the lawn is equal to the vertical component of the force applied, therefore:

where
F is the magnitude of the force applied
is the angle between the direction of the force and the horizontal
In this problem:
F = 120 N
Substituting,

where the negative sign means the direction of the force is downward.
Learn more about vector components and forces here:
brainly.com/question/2678571
brainly.com/question/8459017
brainly.com/question/11292757
brainly.com/question/12978926
#LearnwithBrainly
The acceleration is the correct answer
Answer:
The waves will increase in frequency
Explanation:
As the young girl moves her hand back and forth faster, it will be observed that number of back and forth motions increase every second. Also the distance between crest and trough of the wave (wavelength) will be reduced as she moves her hand back and forth faster.
Frequency = number of turns (moves) per second
The waves will increase in frequency since there will be more number of back and forth motions in every second.
Also,
The distance between crest and trough will be reduced, which implies that there will be decrease in waves wavelength.
This can also be verified using wave equation;
V = Fλ
At constant velocity,
F ∝ ¹/λ
Thus, decrease in wavelength will cause increase in frequency of the waves.
The right answer is : The waves will increase in frequency
Answer:
32%
Explanation:
For a heat engine, efficiency is work out divided by heat in:
η = Wₒ / Qᵢ
Since energy is balanced, heat in is the sum of work out and heat out:
Qᵢ = Wₒ + Qₒ
Therefore:
η = Wₒ / (Wₒ + Qₒ)
Given Wₒ = 710 J and Qₒ = 1480 J:
η = 710 / (710 + 1480)
η = 0.32
The thermal efficiency is 32%.
Answer:true
Explanation:
The lower the refractive index,the faster the velocity of light