60 kg.
The problem involves the concept of weight and gravitational force.
Step 1: Calculate the weight of the barbell using the formula W = mg, where W is the weight, m is the mass, and g is the acceleration due to gravity.
Given: m = 50.0 kg, g = 9.8 m/s^2.
W = 50.0 kg * 9.8 m/s^2 = 490 N.
The problem involves the concept of work and energy.
Step 1: Calculate the work done by the foam pit on the high jumper using the formula W = Fd, where W is the work done, F is the force, and d is the distance.
Given: F = 1200 N, d = 0.4 m.
W = 1200 N * 0.4 m = 480 J.
Step 2: Calculate the kinetic energy of the high jumper before landing using the formula KE = 0.5 * m * v^2, where KE is the kinetic energy, m is the mass, and v is the velocity.
Given: v = 4.0 m/s.
KE = 0.5 * m * (4.0 m/s)^2 = 8.0 m^2/s^2 * m = 8.0 m^2/s^2 * kg.
Step 3: Equate the work done by the foam pit to the change in kinetic energy of the high jumper.
480 J = 8.0 m^2/s^2 * kg.
Step 4: Solve for the mass of the high jumper.
m = 480 J / (8.0 m^2/s^2) = 60 kg.
