D because friction will slow it down going up hills (for safety reasons) and you go really fast going down.
Answer:
Waves transfer energy, not motion
Answer:
W=561.41 J
Explanation:
Given that
m = 51 kg
μk = 0.12
θ = 36.9∘
Lets F is the force applied by man
Given that block is moving at constant speed it mans that acceleration is zero.
Horizontal force = F cos θ
Vertical force = F sinθ
Friction force Fr= μk N
N + F sinθ = m g
N = m g - F sinθ
Fr = μk (m g - F sinθ)
For equilibrium
F cos θ = μk (m g - F sinθ)
F ( cos θ +μk sinθ) = μk (m g
Now by putting the values
F ( cos 36.9∘ + 0.12 x sin36.9∘)=0.12 x 51 x 10
F= 70.2 N
We know that Work
W= F cos θ .d
W= 70.2 x cos 36.9∘ x 10
W=561.41 J
Answer: Option (A) and (D) are the correct statements.
Explanation:
Potential energy is defined as the energy obtained by an object due to its position. Whereas kinetic energy is defined as the energy obtained by an object due to the motion of its molecules.
When there will be only one phase present then addition or removal of energy will lead to change in kinetic energy of the substance but no change in potential energy will take place.
Whereas if change in phase is occurring then adding or removing any energy will lead to change in potential energy of the substance while kinetic energy will remain the same.
Thus, we can conclude that correct statements are as follows.
- While only one phase is present, adding or removing energy changes PE but not KE.
- During a phase change, adding or removing energy changes PE but not KE.
Answer:
1/r
Explanation:
The magnetic field produced by a current in a wire decreases with distance from the wire, this means the magnetic field produced by a currents is inversely proportional to it's distance from the wire.
Let E be magnetic field and r distance of wire
We have that,
E is inversely proportional to r
(E)×(1/r)