KINETIC ENERGY
This type of energy depends on an object’s mass and speed.
What is kinetic energy?
Explanation - KE=1/2mv^2
This type of energy depends on an object’s mass, height, and the gravitational field strength.
What is gravitational potential energy?
Explanation: GPE=mgh
This type of energy is stored in a stretched or compressed spring.
What is elastic potential energy?
E^elastic=1/2kx^2
This is the energy transferred when a force moves an object in the direction of the force.
What is work?
Explanation: W=F*d cos θ
A system is in equilibrium when this net quantity is zero.
What is net force or net energy change?
Explanation: Equilibrium requires no unbalanced forces or energy gradients.
2 kg object moves at 3 m/s. Its kinetic energy is this.
What is 9 J?
Explanation: KE=1/2*2*3^2 =9 J
A 5 kg box is lifted 2 m in a 10 N/kg gravitational field. Its GPE is this.
What is 100 J?
Explanation: GPE=mgh=5⋅10⋅2=100 J
A spring has a spring constant k=200 N/m & is stretched 0.1 m. The energy stored is this.
What is 1 J?
Explanation E=1/2kx^2=1/2(200)(0.12)=1 J
A 10 N force moves an object 3 m in the direction of the force. Work done is this.
What is 30 J?
Explanation: W=Fd =10⋅3=30 J
The equilibrium state of a star or the Earth’s atmosphere is often described by this balance.
What is hydrostatic equilibrium?
Explanation: In a star, outward pressure balances inward gravitational pull; in the atmosphere, pressure gradients balance gravity.
If an object’s speed doubles, its kinetic energy changes by this factor.
What is 4?
explanation: KE ∝ v
doubling speed → 2^2=4
When an object falls, this energy transformation occurs.
What is “GPE converts to kinetic energy”?
Explanation: As height decreases, mgh decreases, KE increases.
Doubling the stretch of a spring changes its stored energy by this factor
What is 4?
Energy ∝ x 2 doubling x → 2^2=4
Power is defined as this quantity divided by time.
What is work or energy?
Explanation P=w/t
This principle is used to determine equilibrium in mechanical systems by summing forces or moments.
What is ΣF=0
Sigma F = 0
ΣF=0
Explanation: Net forces and net torques must vanish for equilibrium.