This is a classic example of conservation of energy. Assuming that there are no losses due to friction with air we'll proceed by saying that the total energy mus be conserved.

Now having information on the speed at the lowest point we can say that the energy of the system at this point is purely kinetic:

Where m is the mass of the pendulum. Because of conservation of energy, the total energy at maximum height won't change, but at this point the energy will be purely potential energy instead.

This is the part where we exploit the Energy's conservation, I'm really insisting on this fact right here but it's very very important, The totam energy Em was

It hasn't changed! So inserting this into the equation relating the total energy at the highest point we'll have:

Solving for h gives us:

It doesn't depend on mass!
Answer:
Acceleration, 
Explanation:
It is given that,
Separation between the protons, 
Charge on protons, 
Mass of protons, 
We need to find the acceleration of two isolated protons. It can be calculated by equating electric force between protons and force due to motion as :


So, the acceleration of two isolated protons is
. Hence, this is the required solution.
Answer:
angle is denoted by /_ , see in explanation
According to Newton's Second Law:
F = m*a = 2000 kg*3.5 m/s^2 = 7000 N
Answer:
24.3KW
Explanation:
A)The kinetic energy is changing, the potential energy is changing and the chemical energy in form of fuel powering the engine also is changing
The kinetic energy is increasing as the body gain speed, the potential energy also increases as the body gain height against gravity and the chemical energy in form of fuel decreases as the body burn the fuel to create a lifting force
B) The workdone by the lifting force = the change in kinetic energy + the change in potential energy
C)The time taken in seconds to do the work is the variable needed
D) average power generated by the lifting force = (change in kinetic energy + change in potential energy) / time taken in seconds
Average power = 1/2 * m(mass) (Vf-Vi)^2 + mg(hf-hi) /t where vf is final speed and vi is initial speed at rest = 0, similarly, hf = final height and hi = initial height.
Average power = 1/2*810*7^2 + 810*9.81*8.2/3.5s
Average power = (19845+65158.02)/3.5 = 24286.577 approx 24.3kW