Answer:
it is chemical reactivity (D)
Explanation:
it is because chemical properties are properties that can be measured and observed only when matter undergoes a change to become an entirely different kind of matter.Which they include Chemical reactivity,flammable,and the ability to rust.And Chemical reactivity is the ability of matter to react chemically with other substances.
Answer:
α = 0
, w = w₀
Explanation:
Torque is related to angular acceleration by Newton's second law for rotational motion.
τ = I α
Where τ is the torque, I the moment of inertia and α the angular acceleration.
If we apply an external torque for the sum of all torques to be zero, the angular acceleration must fall to zero
α = 0
Since the acceleration is zero, the angular velocity you have at that time is constantly killed.
w = w₀ + α t
w = w₀ + 0
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
