When the ruler is broughı near the inetal knob, it repels electrons in the metal. Electrons move away froni the ruler and down the metal rod. The knob now has a positive charge. The thin pieces of metal foil at the bottom of the metal rod now have a negative charge.
A 1.5 kg bird is gliding at a height of 12 m with a speed of 3.8m/s. The kinetic energy of the bird is 10.83 joules.
Explanation:
Kinetic energy can be defined as,The kinetic energy (KE) of an object is the energy that the object possesses due to its motion.
The Kinetic energy can be calculated by using formula,
Kinetic Energy: KE = 1/2 (mv 2)
Where, m = Mass, v = Velocity.
Here in this case the bird mass is 1.5kg and is gliding with velocity 3.8m/s
hence, KE= 1/2*(1.5)×(3.8)^2
=0.5×1.5×3.8×3.8
=10.83Joules
Since momentum is a vector quantity, take any direction as positive and other as negative. Answer won't change.
