Answer:
The mass of the object is 133.33 kg
Step-by-step explanation:
From Newton's second law of motion
F = ma
Where F is the force
m is the mass
and a is the acceleration
From the question,
A stationary object is pushed with a force of 400N, that is F = 400N. To determine the mass of the object,
First, we will determine the acceleration.
From one of the equations of kinematics for linear motion,
v = u + at
Where v is the final velocity
u is the initial velocity
a is the acceleration
and t is time
We can write that
v - u = at
Then, a = (v - u) / t
From the question,
t = 8s
v = 24m/s
u = 0 m/s (Since the object was stationary, that is, it was pushed from rest)
∴ a = (24m/s - 0m/s) / 8s
a = 24 / 8 = 3 m/s²
Therefore, acceleration is 3 m/s²
Now,
From F = ma
m = F / a
From the question
F = 400N
∴ m = 400N / 3m/s²
m = 133.33 kg
Hence, the mass of the object is 133.33 kg.