# Force and Perfectly Elastic Question

Topics: Force, Mass, Energy Pages: 3 (857 words) Published: December 5, 2014
﻿Test1
Question no 9) A package is dropped from a helicopter moving upward at 15m/s If it takes16 sec before the package strikes the ground, how high above the ground was the package when it was released if air resistance is negligible? Ans) 1000m

Question no. 11) If A -B = 0, then the vectors A and B have equal magnitudes and are directed in the opposite directions from each other. Ans) False
Question no. 16) A monkey is sitting at the top of a tree 20 m above ground level. A person standing on the ground wants to feed the monkey. He uses a bow and arrow to launch the food to the monkey. If the person knows that the monkey is going to drop from the tree at the same instant that the person launches the food, how should the person aim the arrow containing the food? Air resistance is small enough to be ignored. Ans) He should aim it at the monkey.

Question no 18)An object has a position given by r= [2.0 m + (5.00 m/s)t]i + [3.0 m - (2.00 m/s2)t2]j, where quantities are in SI units. What is the speed of the object at time t=2sec? Ans) 9.43m/s

Test 2:

Question no 16)In order to lift a bucket of concrete, you must pull up harder on the bucket than it pulls down on you. Ans) False
Question no 17 )Two weights are connected by a massless wire and pulled upward with a constant speed of 1.50 m/s by a vertical pull P. The tension in the wire is T (see figure). Which one of the following relationships between T and P must be true? Ans) P= T+25N UNIT IS Newton(N)

Question no 22) If you swing a bucket of water fast enough in a vertical circle, at the highest point the water does not spill out because an outward force balances the pull of gravity on the water. Ans) False

Question no 23)Suppose a highway curve is properly banked to eliminate friction for a speed of 45 mph. If your tires were bald and you wanted to avoid sliding on the road, you would have to drive Ans) at exactly 45mph

question no 25) A 23 kg mass is connected to a nail on a frictionless table...