John can run with the velocity of 5 m/s
Explanation:
- Kinetic energy is defined as the energy is being used to do an activity, basically energy associated with the motion of objects in the universe.
- The formula used to find the kinetic energy of an object is k = where as k represented as kinetic energy, m is the mass of the object and v is the velocity of the given object.
- Here, to find the answer we have to re-write the equation as
- Given, the mass of the object, here it is John = 80 kg, energy needs to be converted to kinetic energy, k = 1000 J.
- Hence, substitute all the values, then you would velocity as 5 m/s
Answer:
If force is applied to cause the motion of the body
Explanation:
In the setup given in this diagram, potential energy can be converted into kinetic energy by applying force on the cart or object to move it down the slope.
Potential energy is the energy due to the position of a body. The body has huge potential energy at its current position.
Kinetic energy is the energy due to the motion of a body.
As the body moves down the slope and its velocity increases, it gains massive kinetic energy.
Down the slope, the kinetic energy increases as the potential energy decreases.
At the bottom of the slope, the potential energy becomes zero and the kinetic energy is at its maximum.
Answer:
0.0268 m
Explanation:
Draw a free body diagram of the block. There are three forces: weight force mg pulling down, buoyancy of the oil B₁ pushing up, and buoyancy of the water B₂ pushing up.
Sum of forces in the y direction:
∑F = ma
B₁ + B₂ − mg = 0
ρ₁V₁g + ρ₂V₂g − mg = 0
ρ₁V₁ + ρ₂V₂ = m
ρ₁V₁ + ρ₂V₂ = ρV
ρ₁Ah₁ + ρ₂Ah₂ = ρAh
ρ₁h₁ + ρ₂h₂ = ρh
(930 kg/m³)h₁ + (1000 kg/m³)h₂ = (968 kg/m³) (4.93 cm)
Since the block is fully submerged, h₁ + h₂ = 4.93 cm.
(930 kg/m³) (4.93 cm − h₂) + (1000 kg/m³)h₂ = (968 kg/m³) (4.93 cm)
h₂ = 2.68 cm
h₂ = 0.0268 m
Answer:
20 J
Explanation:
The law of conservation of energy states that (if we neglect air resistance) the mechanical energy of an object in free fall is conserved:
where
E is the mechanical energy, which is the sum of
U = potential energy
K = kinetic energy
When the ball is held 10 meters above the ground, its gravitational potential enegy is U = 20 J, while its kinetic energy is K = 0 (because the ball is at rest). Therefore, its mechanical energy is
E = U + K = 20 J + 0 = 20 J
Just before hitting the ground, its potential energy is zero (because its height is now zero), and since the mechanical energy must be conserved, we still have that E = 20 J. So, we can find the kinetic energy just before hitting the ground: