Menu div.question,div.steps {font-size: 16px; padding: 10px;line-height: 20px; margin: 20px;} div.question{border: 1px solid #ccc;} div#solution .button{font-size: 20px; margin: 20px; width: 200px; padding: 10px; text-align: center;} div.hint,div.answer,div.steps{display: none;} div.pre_next{font-size: 30px; width:90%; margin:auto;} div.pre_next a.nav_pre{float:left;} div.pre_next a.nav_next{float:right;} div.title div.notes{ font-family:sans-serif, Arial; font-size: 18px; } div.speak{display:none;} i.speak{float: right;margin-top:-10px;cursor:pointer;} 4. A pendulum bob of mass 1.5 kg, swings from a height A to the bottom of its arc at B. The velocity of the bob at B is 4.0\ m//s. Calculate the height A from which the bob was released. Ignore the effects of air friction.4. A pendulum bob of mass 1.5 kg, swings from a height A to the bottom of its arc at B. The velocity of the bob at B is 4.0\ m//s. Calculate the height A from which the bob was released. Ignore the effects of air friction. Hint KE + PE = constant Answer h = 0.80\ m Show Steps Given: v_B = 4.0 m//s Equations KE + PE = constant Solution: KE_A + PE_A = KE_B + PE_B 0 + mgh = 1/2mv_B^2 + 0 h = v_B^2/(2g) h = (4.0 m//s)^2/(2 times 10\ m//s^2) h = 0.80\ m