Answer:
The work done by the weightlifter, W = 700 J
The power of the weightlifter, P = 350 watts
Explanation:
A weightlifter lifts a set of weights a vertical distance, s = 2 m
The force exerted to lift the weight, F = 350 N
The work done by the body is defined as the product of the force applied by the body to the displacement it caused.
W = F x s
= 350 N x 2 m
= 700 J
The work done by the weightlifter, W = 700 J
The time taken by the weightlifter to lift the weight, t = 2 s
The power is defined as the rate of body to do work. It is given by the equation,
P = W / t
= 700 J / 2 s
= 350 watts
Hence, the power of the weightlifter, P = 350 watts
<h3>
Answer:</h3>

<h3>
General Formulas and Concepts:</h3>
<u>Math</u>
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Physics</u>
<u>Energy</u>
Elastic Potential Energy: 
- U is energy (in J)
- k is spring constant (in N/m)
- Δx is displacement from equilibrium (in m)
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
k = 7.50 N/m
Δx = 0.40 m
<u>Step 2: Find Potential Energy</u>
- Substitute in variables [Elastic Potential Energy]:

- Evaluate exponents:

- Multiply:

- Multiply:

To solve this problem we will apply the concept related to the electric field. The magnitude of each electric force with which a pair of determined charges at rest interacts has a relationship directly proportional to the product of the magnitude of both, but inversely proportional to the square of the segment that exists between them. Mathematically can be expressed as,

Here,
k = Coulomb's constant
V = Voltage
r = Distance
Replacing we have


Therefore the magnitude of the electric field is 
Let
A = the amplitude of vibration
k = the spring constant
m = the mass of the object
The displacement at time, t, is of the form
x(t) = A cos(ωt)
where
ω = the circular frequency.
The velocity is
v(t) = -ωA sin(ωt)
The maximum velocity occurs when the sin function is either 1 or -1.
Therefore

Therefore

The KE (kinetic energy) is given by

The PE (potential energy) is given by

When the KE and PE are equal, then

For the oscillating spring,

Therefore

Answer: