(a) The skater covers a distance of S=50 m in a time of t=12.1 s, so its average speed is the ratio between the distance covered and the time taken:

(b) The initial speed of the skater is

while the final speed is

and the time taken to accelerate to this velocity is t=2 s, so the acceleration of the skater is given by

(c) The initial speed of the skater is

while the final speed is

since she comes to a stop. The distance covered is S=8 m, so we can use the following relationship to find the acceleration of the skater:

from which we find

where the negative sign means it is a deceleration.
Explanation:
Efficiency is the ratio of energy out to energy in.
e = Eout / Ein
0.52 = 800 J / Ein
Ein ≈ 1538 J
Round as needed.
The correct answer is the wavelength of the light. Good luck m8
Answer:
3600 kg
Explanation:
From the question,
Density = Mass/Volume
D = M/V.............................. Equation 1
Where D = Density of the substance, M = mass of the substance, V = Volume of the subtance.
Make M the subject of the equation
M = D×V ............................ Equation 2
Given: D = 1200 kg/m³, V = 3 m³.
Substitute these values into equation 2
M = 1200×3
M = 3600 kg.
Hence the mass of the substance is 3600 kg
Qualitative data is easy to explain. You either agree or disagree in writing. Wrong. You agree, disagree, or qualify. Meaning agree to somewhat extend, but not entirely. So you can agree that people should walk instead of talk in the progressive manner, but not in the impulsive manner.