Answer:
Minimum work = 5060 J
Explanation:
Given:
Mass of the bucket (m) = 20.0 kg
Initial speed of the bucket (u) = 0 m/s
Final speed of the bucket (v) = 4.0 m/s
Displacement of the bucket (h) = 25.0 m
Let 'W' be the work done by the worker in lifting the bucket.
So, we know from work-energy theorem that, work done by a force is equal to the change in the mechanical energy of the system.
Change in mechanical energy is equal to the sum of change in potential energy and kinetic energy. Therefore,

Therefore, the work done by the worker in lifting the bucket is given as:

Now, plug in the values given and solve for 'W'. This gives,

Therefore, the minimum work that the worker did in lifting the bucket is 5060 J.
Answer: ma is the formula of Newton's Second Law of Motion. Newton's Second Law of Motion is defined as Force is equal to the rate of change of momentum. For a constant mass, force equals mass times acceleration.
Explanation: Newton's second law of motion is F = ma, or force is equal to mass times acceleration.
As proton is heavier then electron, and electrostatic force is directly proportional to mass, so it would be greater and direction would be changed 'cause of different charges.
In short, Your Answer would be Option 4
Hope this helps!
Answer:
1449 K
Explanation:
The surface temperature of a star is related to its peak wavelength by Wien's displacement law:

where
T is the surface temperature
b is Wien's displacement constant

So the surface temperature of the star is

The law of motion that is being described in this scenario is Friction. Friction between the skate and the ice is what's moving the skater forward.