Answer:
All of these answers are dependent upon the specific scenario, but here are some general answers.
1. An object with a greater height will have more potential energy.
2. Potential energy can be changed into kinetic energy as an object falls. It loses height (potential energy) and gains speed (kinetic energy).
3. Depends on what scenario your class had.
Answer:
K.E = 30,000 J
Explanation:
Given,
The potential energy of the roller coaster car, P.E = 40000 J
The kinetic energy at height h/4, K.E = ?
According to the law of conservation of energy, the total energy of the system is conserved.
At height 'h', the total energy is,
P.E = mgh
K.E = 0
At height 'h/4', the total energy is
P.E + K.E = mgh
P.E = mgh/4
K.E = 1/2 mv²
Therefore,
mgh/4 + 1/2 mv² = mgh
gh/4 + v²/2 = gh
Hence,
v² = 3gh/2
Substituting in the K.E equation
K.E = 1/2 mv²
= 1/2 m (3gh/2)
= 3/4 mgh
= 3/4 x 40000
= 30000 J
Hence, the K.E of the roller coaster car is, K.E = 30000 J
Answer:
Explanation:
Given
Wavelength of green light 
For destructive interference by reflection the path difference is an integral multiple of wavelength so
where 
n=refractive index of medium
suppose water is the medium
so
Answer:
0.0126°C
Explanation:
Kinetic energy sustain by the block,K.E = 1/2× mass×velocity^2
K.E = 1/2 ×1.3×(4^2)
=1/2 × 1.3× 16 = 1.3 ×8 = 10.4J
The internal energy is 71% of kinetic energy is;
U= 71/100 × 10.4 = 7.38J
But U = m × C × ∆T
Where U is internal energy
m is the mass of iron
C is the heat capacity of iron
∆T is the temperature change
By make ∆T the subject of the formula we have
∆T=U/ m×C
=7.38/ 1.3×452= 0.0126°C
