Answer:
6.13428 rev/s
Explanation:
= Final moment of inertia = 4.2 kgm²
I = Moment of inertia with fists close to chest = 5.7 kgm²
= Initial angular speed = 3 rev/s
= Final angular speed
r = Radius = 76 cm
m = Mass = 2.5 kg
Moment of inertia of the skater is given by
![I_i=I+2mr^2](https://tex.z-dn.net/?f=I_i%3DI%2B2mr%5E2)
In this system the angular momentum is conserved
![L_f=L_i\\\Rightarrow I_f\omega_f=I_i\omega_i\\\Rightarrow \omega_f=\dfrac{I_i\omega_i}{I_f}\\\Rightarrow \omega_f=\dfrac{(5.7+2\times 2.5\times 0.76^2)3}{4.2}\\\Rightarrow \omega_f=6.13428\ rev/s](https://tex.z-dn.net/?f=L_f%3DL_i%5C%5C%5CRightarrow%20I_f%5Comega_f%3DI_i%5Comega_i%5C%5C%5CRightarrow%20%5Comega_f%3D%5Cdfrac%7BI_i%5Comega_i%7D%7BI_f%7D%5C%5C%5CRightarrow%20%5Comega_f%3D%5Cdfrac%7B%285.7%2B2%5Ctimes%202.5%5Ctimes%200.76%5E2%293%7D%7B4.2%7D%5C%5C%5CRightarrow%20%5Comega_f%3D6.13428%5C%20rev%2Fs)
The rotational speed will be 6.13428 rev/s
Boomerang has a curve the airplane propeller is four paddles
First we write the corresponding kinematics equations:
a = -g
v = -g * t + vo
y = -g * ((t ^ 2) / 2) + vo * t + yo
Substituting the values:
y = - (9.81) * (((0.50) ^ 2) / 2) + (19) * (0.50) + (0) = 8.27m
answer:
the displacement at the time of 0.50s is 8.27m
Answer:
3520
Explanation: Force = Mass x Acceleration [∴ or F = ma]. Given values. mass, m = 1600 kg; initial velocity, u = 8 m/s; final velocity, v = 30 m/s; time taken, t = 10 s.
Answer:
The answer is E) 20kPa
Explanation:
Here we use the definition of Pressure: Pressure is a physical quantity that measures the projection of force in the perpendicular direction per unit area. In this case, wehave a 200N Force over a 100cm^2 Area
In order to have the pressure in international units we need to convert those cm^2 to m^2 this way:
We know 100cm is equal to 1m
In this case, the area will be equal to 0,01m^2
With this information we use the Pressure equation, which based on the definition will be:
Solving:
Then P is the same as 20kPa