Answer:
The ball has an initial linear kinetic energy and initial rotational kinetic energy which can both be converted into gravitational potential energy. Therefore the hill with friction will let the ball reach higher.
Explanation:
The ball has an initial linear kinetic energy and initial rotational kinetic energy which can both be converted into gravitational potential energy. Therefore the hill with friction will let the ball reach higher.
This is because:
If we consider the ball initially at rest on a frictionless surface and a force is exerted through the centre of mass of the ball, it will slide across the surface with no rotation, and thus, there will only be translational motion.
Now, if there is friction and force is again applied to the stationary ball, the frictional force will act in the opposite direction to the force but at the edge of the ball that rests on the ground. This friction generates a torque on the ball which starts the rotation.
Therefore, static friction is infact necessary for a ball to begin rolling.
Now, from the top of the ball, it will move at a speed 2v, while the centre of mass of the ball will move at a speed v and lastly, the bottom edge of the ball will instantaneously be at rest. So as the edge touching the ground is stationary, it experiences no friction.
So friction is necessary for a ball to start rolling but once the rolling condition has been met the ball experiences no friction.
Answer:
D. shortest wavelength
Explanation:
Photons with the highest energy have the shortest wavelength. The shorter the wavelength, the higher the energy of a photon.
A photon is a quantity that transmits electromagnetic energy from one place to the other.
- Gamma rays have photons that transmits the highest amount of energy.
- The rays have the shortest wavelength and highest frequency of all electromagnetic radiations.
Energy, wavelength and frequency of a photon are connected using the expression:
E = h f = 
E is the energy
h is the Planck's constant
f is the frequency.
I think the answer is 2 hope it helps
