Saved Bookmarks
| 1. |
A projectile is fired at 30• with momentum p, neglecting friction, change in K. E, when it returns back to ground will be??? |
|
Answer» Given : PROJECTION angle of the PROJECTILE = 30° Momentum with which it is projected = p To FIND : Assuming no friction change in Kinetic energy when it RETURNS back to the ground = ? Solution : Since there is no friction , so we can apply Law of Energy CONSERVATION, i.e. Change in potential energy will be equal to change in Kinetic energy, so : ∴U = mgh ⇒ΔU =mgΔh Since the projectile is back on the ground so Δh= 0 Hence ΔU = 0 Now since ΔU = 0 , so ΔKE should also be 0 . So, when the particle returns back to the ground , its change in K.E. will be 0 . |
|