Let F be the force acting on the bowling ball.
Work done by force= change in KE
Let F be the force acting on the bowling ball
Work done by force = change in KE
F .d = 0.5 m V^2 + 0.5 x I x w^2
F d = 0.5 m ( 1+l) V^2
Solve accordingly to get the answer.
Answer:
There are 934 excess electrons on the ball with charge -1.4944*10^(-16).
Step-by-Step Explanation:
A ball will usually be neutral and have no charge on it.
If it is negatively charged, it means there are excess electrons on it.
If we know the charge on the ball, we can count the excess no. of electrons.
We know that the charge on the ball = c = -1.4944*10^-16
Charge of one electron = e = 1.6*10^-19
Charge of n electrons on the ball = ne = c
⇒ n = c/e
n = (-1.4944*10^-16)/(1.6*10^-19)
n = 934 electrons
Answer:
a) a = 0.477 m/s^2
b) u = 0.04862
Explanation:
Given:-
- The rotational speed of the turntable N = 33 rev/min
- The watermelon seed is r = 4.0 cm away from axis of rotation.
Find:-
(a) Calculate the acceleration of the seed, assuming that it does not slip. (b) What is the minimum value of the coefficient of static friction between the seed and the turntable if the seed is not to slip
Solution:-
- First determine the angular speed (w) of the turntable.
w = 2π*N / 60
w = 2π*33 / 60
w = 3.456 rad/s
- The watermelon seed undergoes a centripetal acceleration ( α ) defined by:
α = w^2 * r
α = 3.456^2 * 0.04
α = 0.477 m / s^2
- The minimum friction force (Ff) is proportional to the contact force of the seed.
- The weight (W) of the seed with mass m acts downwards. The contact force (N) can be determined from static condition of seed in vertical direction.
N - W = 0
N = W = m*g
- The friction force of the (Ff) is directed towards the center of axis of rotation, while the centripetal force acts in opposite direction. The frictional force Ff = u*N = u*m*g must be enough to match the centripetal force exerted by the turntable on the seed.
Ff = m*a
u*m*g = m*a
u = a / g
u = 0.477 / 9.81
u = 0.04862
Answer:
![v(0)=2m/s](https://tex.z-dn.net/?f=v%280%29%3D2m%2Fs)
Explanation:
The instantaneous velocity of a point mass that executes a simple harmonic movement is given by:
![v(t)=\omega *A*cos(\omega t + \phi)](https://tex.z-dn.net/?f=v%28t%29%3D%5Comega%20%20%2AA%2Acos%28%5Comega%20t%20%2B%20%5Cphi%29)
Where:
![\omega=Angular\hspace{3}frequency\\A=Amplitude\\\phi=Initial\hspace{3}phase](https://tex.z-dn.net/?f=%5Comega%3DAngular%5Chspace%7B3%7Dfrequency%5C%5CA%3DAmplitude%5C%5C%5Cphi%3DInitial%5Chspace%7B3%7Dphase)
Express the amplitude in meters:
![10cm*\frac{1m}{100cm} =0.1m](https://tex.z-dn.net/?f=10cm%2A%5Cfrac%7B1m%7D%7B100cm%7D%20%3D0.1m)
The angular frequency can be found using the next equation:
![\omega=\sqrt{\frac{k}{m} }](https://tex.z-dn.net/?f=%5Comega%3D%5Csqrt%7B%5Cfrac%7Bk%7D%7Bm%7D%20%7D)
Using the data provided:
![\omega=\sqrt{\frac{400}{1} } =20](https://tex.z-dn.net/?f=%5Comega%3D%5Csqrt%7B%5Cfrac%7B400%7D%7B1%7D%20%7D%20%3D20)
At the equilibrium position:
![\phi=0](https://tex.z-dn.net/?f=%5Cphi%3D0)
![v(0)=20*(0.1)cos(20*0+0)=2*cos(0)=2*1=2m/s](https://tex.z-dn.net/?f=v%280%29%3D20%2A%280.1%29cos%2820%2A0%2B0%29%3D2%2Acos%280%29%3D2%2A1%3D2m%2Fs)