Answer:
a. negative
b. zero
Explanation:
work is the change in the energy of a system due to external forces
work is done when a force moves a load through a distance in the direction of the force
The work done by a force on a system is positive when the force and the force displacement point in the same direction and negative when they point in opposite directions
in the scenario we are considering in the question, the force (the hand) moves the block vertically upwards but the displacement of the block reduces (in the opposite direction) since it decelerates. as such the work done by gravity on the block is negative.
the work done on the block is zero if the system consists of the block and the earth because there is no gravitational force exerted on the system
Answer:
first one i think is this. work = 1/2 kx^2 = 1/2 Fx
2nd, is 0.08 J
Explanation:
EE = ½ kx²
EE = ½ (400 N/m) (0.02 m) ²
EE = 0.08.
THIRD, Velocity of the stone is 4 m/s when it leaves catapult.
Mass is <span>is a dimensionless quantity representing the amount of matter in a particle or object. The more mass something has, the more energy is used to lift it.</span>
