Under the action of the force F = 50 N, the body moves rectilinearly so that the dependence of the path s traveled by the body

Under the action of the force F = 50 N, the body moves rectilinearly so that the dependence of the path s traveled by the body on time t is given by the equation s (t) = 5-2t + 4t ^ 2m. Find the mass m of the body.

According to Newton’s second law:
F = m * a, where F is the force that acts on the body (F = 50 N), m is the body weight (kg), and is the acceleration of the body (m / s²).
To find the acceleration of the body from the function S (t) = 5 – 2t + 4t², it is necessary to take the double derivative (second order derivative) from this function:
x ‘= V = (5 – 2t + 4t²)’ = 0 – 2 + 8t = -2 + 8t.
x ” = S ” = V ‘= a = (-2 + 8t)’ = 0 + 8 = 8 m / s².
Let’s express and calculate the body weight:
m = F / a = 50/8 = 6.25 kg.
Answer: Body weight is 6.25 kg.