Answer:
K = -½U
Explanation:
From Newton's law of gravitation, the formula for gravitational potential energy is;
U = -GMm/R
Where,
G is gravitational constant
M and m are the two masses exerting the forces
R is the distance between the two objects
Now, in the question, we are given that kinetic energy is;
K = GMm/2R
Re-rranging, we have;
K = ½(GMm/R)
Comparing the equation of kinetic energy to that of potential energy, we can derive that gravitational kinetic energy can be expressed in terms of potential energy as;
K = -½U
The gravitational potential energy will increase by 423.36 J
<h3>How to determine the potential energy at ground level</h3>
- Mass (m) = 72 kg
- Acceleration due to gravity (g) = 9.8 m/s²
- Height (h) = 0 m
- Potential energy at ground level (PE₁) =?
PE = mgh
PE₁ = 72 × 9.8 × 0
PE₁ = 0 J
<h3>How to determine the potential energy at 60 cm (0.6 m)</h3>
- Mass (m) = 72 kg
- Acceleration due to gravity (g) = 9.8 m/s²
- Height (h) = 0.6 m
- Potential energy at 60 cm (0.6 m) (PE₂) =?
PE = mgh
PE₂ = 72 × 9.8 × 0.6
PE₂= 423.36 J
<h3>How to determine the change in potential energy </h3>
- Potential energy at ground level (PE₁) = 0 J
- Potential energy at 60 cm (0.6 m) (PE₂) = 423.36 J
- Change in potential energy =?
Change in potential energy = PE₂ - PE₁
Change in potential energy = 423.36 - 0
Change in potential energy = 423.36 J
Learn more about energy:
brainly.com/question/10703928
#SPJ1
Protons are positively charged and neutrons are neutral whereas electrons are negatively charged.
Answer:
D. the linear velocity of the point of contact (relative to the inclined surface) is zero
Explanation:
The force of friction emerges only when there is relative velocity between two objects . In case of perfect rolling , there is no sliding so relative velocity between the surface and the point of contact is zero . In other words the velocity of point of contact becomes zero , even though , the whole body is in linear motion . It happens due point of contact having two velocities which are equal and opposite . One of the velocity is in forward direction and the other velocity which is due to rotation is in backward direction . So net velocity of point of contact becomes zero . Due to absence of sliding , displacement due to friction becomes zero . Hence work done by friction becomes zero.
