A rocket blasts off from rest and attains a speed of 58.9 m/s in 14.4 s. An astronaut has a mass of 57.5 kg. What is the astronaut's apparent weight during takeoff?

Answer 1

When doing these types of physic problems or actually any physics problem, write down what's given.

m=57.5 kg
v_f= 58.9 m/s
v_i = 0 (because it was a rest, not moving)
t = 14.4 s
g=9.81 m/s^2

The apparent weight is:

W = F + m*g

F=ma

Everything is given to us in the problem except for a, which is acceleration.

a=deltaV/t

deltaV = v_f-v_i

a=(58.9-0)/14.4

a= 4.1 m/s^2

so now lets go back to your two main equation:

W=F+m*g

where F = m*a
F=57.7*4.1
F = 235.75 N

W=235.75 + (57.5*9.81)

W = 799.825 N