Chapter 5 Circular Motion

221. Centripetal force is also called Seeking force 

222. Moment of inertia or rotational inertia(I) is equal to mr2 

223. In absence of external torque the angular momentum of system remains  Constant 

224. The minimum required velocity to put a satellite into the orbit is called Critical velocity (7.9 km-1) 

225. The speed of satellite is inversely proportional to its Radius 

226. The time which is taken by geostationary satellite or geosynchronous to complete round around the earth is 24 hours 

227. The geostationary orbit has an altitude of  22,240 miles (35,790 km) 

228. The geostationary orbit has an speed of  6,880 mph (11,070 kmh-1) 

229. The radius of geostationary satellite from center of the earth is 4.23 x 104 km

230. The radius of the earth is 6.4 x 106 m 

231.  A body weight in upward moving lift  Increases 

232. A body weight in lift at rest is Constant 

233. A body weight in downward moving lift Decreases 

234. In absence of an external torque, the angular momentum of rotating body is constant 

235. The dimension of angular acceleration is [T-2 ] 

236. Motion of the bob of the simple pendulum is slowest at the Equator of earth 

237. If the coplanar forces acting on the body keep it in the equilibrium then these forces are Concurrent 

238. The angle between linear and angular velocity is 900

239. If the area of the circle is equal to its circumstance , the radius of the circle is 1 

240. A body weight in freely falling lift is Zero 

241. When satellite is falling freely everything in this appears to be Weightless 

242. Momentum is conserved providing no external force act Principle of conservation of momentum 

243. A body in equilibrium must have not Acceleration 

244. The escape velocity from the earth gravitational field depends on Radius of earth and g 

245. The geostationary satellites are rotating with the speed of Earth 

246. The magnitude of periodic force, which the simple pendulum exert on the suspension point depends on Value of g 

247. Angular acceleration is produced by Torque 

248. The escape velocity of any mass from earth is 11x 103 m s-1     Or 11km s-1  

249. The escape velocity from any planet depends on radius and mass of that  Planet 

250. The gravitational potential energy per unit mass is called Gravitational potential 

251. The orbital velocity of satellite in an orbit around the earth depends upon  Radius of the orbit 

252. The value of G at the moon as compared to earth is  Smaller (one sixth) 

253. The time period of communication satellite is 24 hour 

254. The displacement of a body in circle is called  Angular displacement  

255. 1rev=  2π radian  

256. 1 radian =  57.30 

257. Longitude of the place does not affect the value of  G  

258. The value of g is affected by the  Latitude of place  

259. The value of g is affected by the Depth of place  

260. The value of g is affected by the Attitude of place 

261. SI unit of angular displacement is  Radian  

262. SI unit of angular velocity is  Radian/sec  

263. The direction of angular velocity of a body moving in a circle is  Along the tangent 

265. The direction of angular velocity is given by  Right hand rule  

266. The rate of change of angular velocity is called  Angular acceleration  

267. SI unit of angular acceleration  Rad sec-2 

268. The dimension of angular acceleration are  [T-2] 

269. The relation between linear and angular acceleration are  a = r α 

270. The vectorical form of angular acceleration is  -ω2 r 

271. The force headed to keep to keep the body in acceleration is called  Centripetal force  

273. Angular momentum is conserved under  Central force  

274. When the body is moving with uniform acceleration in circle, here constant is  Magnitude  

275. The direction of body moving with uniform acceleration is  Variable  

276. K.E and angular momentum of a body is related by  K.E = ½ Lω 

278. The moment of inertia of body depends upon mass and  Distribution with respect to axis of rotation (I=mr0)

279. Centripetal acceleration is always directed towards the  Center of circle  

280. In a gymnast rotating on rotating stool with his stretched arms, he lowers his arms. The angular speed will  Increase (L=Iω) 

281. Centripetal force performs  Zero work  (d=0) 

282. When body is whirled in vertical circle at the end of the string tension in the string is maximum  At the bottom (T=Fc + w) 

284. The angular speed for daily rotation of earth in rad s-2 is  7.5 x 10-5 

285. When external force acting on a system is constant, angular momentum is  Conserved  

286. When the body moves in circular path, its velocity remains  Changes continuously  

288. The dimension of moment of inertia  [ML-2] 

289. The law of gravitation was introduced by  Newton

290. According to Einstein’s theory space time is  Curved