A helicopter flying west begins experiencing an acceleration of 3m/s2 east. Will the magnitude of its velocity increase or decre
1 answer:
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Answer:
Average = 11.25 cm
standard deviation = 0.129 cm
Explanation:
The data provided in the question is:
x₁ = 11.4 cm
x₂ = 11.3 cm
x₃ = 11.2 cm
x₄ = 11.1 cm
total number of data points, N = 4
Now, the average is calculated as:
Average =
substituting the values in the above formula we get,
Average =
Average = 11.25 cm
Now the standard deviation is calculated as:
standard deviation =
substituting the values in the above equation we get,
standard deviation =
or
standard deviation = 0.129 cm
Answer:
The skater covers a distance of <u>15 m</u> before stopping.
Explanation:
Let the distance traveled before stopping be 'd' m.
Given:
Mass of the skater (m) = 90 kg
Initial velocity of the skater (u) = 12.0 m/s
Final velocity of the skater (v) = 0 m/s (Stops finally)
Coefficient of kinetic friction (μ) = 0.490
Acceleration due to gravity (g) = 9.8 m/s²
Now, we know that, from work-energy theorem, the work done by the net force on a body is equal to the change in its kinetic energy.
Here, the net force acting on the skater is only frictional force which acts in the direction opposite to motion.
Frictional force is given as:
Where, 'N' is the normal force acting on the skater. As there is no vertical motion,
∴
Now, work done by friction is a negative work as friction and displacement are in opposite direction and is given as:
Now, change in kinetic energy is given as:
Therefore, from work-energy theorem,
Hence, the skater covers a distance of 15 m before stopping.