Answer:
Part a)

Part b)

Part c)
Speed is more than the required speed so it will reach the top
Explanation:
Part a)
As we know that there is no frictional force while block is moving on horizontal plane
so we can use energy conservation on the block



Part b)
If the track has average frictional force of 7 N then work done by friction while block slides up is given as



work done against gravity is given as



Now by work energy equation we have



Part c)
now minimum speed required at the top is such that the normal force must be zero



so here we got speed more than the required speed so it will reach the top
The kinetic energy of the child at the bottom of the incline is 106.62 J.
The given parameters:
- <em>Mass of the child, m = 16 kg</em>
- <em>Length of the incline, L = 2 m</em>
- <em>Angle of inclination, θ = 20⁰</em>
The vertical height of fall of the child from the top of the incline is calculated as;

The gravitational potential energy of the child at the top of the incline is calculated as;

Thus, based on the principle of conservation of mechanical energy, the kinetic energy of the child at the bottom of the incline is 106.62 J since no energy is lost to friction.
Learn more about conservation of mechanical energy here: brainly.com/question/332163
Complete Question
A parallel plate capacitor creates a uniform electric field of 5 x 10^4 N/C and its plates are separated by 2 x 10^{-3}'m. A proton is placed at rest next to the positive plate and then released and moves toward the negative plate. When the proton arrives at the negative plate, what is its speed?
Answer:

Explanation:
From the question we are told that:
Electric field 
Distance 
At negative plate
Generally the equation for Velocity is mathematically given by

Therefore




Answer:
Option (B)
Explanation:
A lift chart usually refers to a graphical representation that is mainly used in order to improve the drawbacks of a mining model by making a comparison with any random guess, and also helps in determining the changes that occur in terms of lift scores.
It describes the binary classification of the problems associated with the mining activity. This type of chart is commonly used to differentiate the lift scores for a variety of models, and picking the best one out of all.
Thus, the correct answer is option (B).