Final answer:
To find the mass of the body, we can use Newton's second law of motion, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration. In this case, the mass of the body is 6.0 kg.
Step-by-step explanation:
To find the mass of the body, we can use Newton's second law of motion, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration. In this case, we have two forces acting on the object with magnitudes of 25 N and 45 N and an acceleration of 10.0 m/s². Since the forces are not in the same direction, we need to find their resultant force. We can do this using vector addition.
The resultant force, FR, can be found using the formula FR = sqrt(F₁² + F₂² + 2F₁F₂cosθ), where F₁ and F₂ are the magnitudes of the two forces and θ is the angle between them. Plugging in the values, we get FR = sqrt(25² + 45² + 2(25)(45)cos70°) = 61.74 N.
Now we can use Newton's second law to find the mass of the body. FR = m * a, where FR is the resultant force, m is the mass of the body, and a is the acceleration. Rearranging the equation, we have m = FR / a = 61.74 N / 10.0 m/s² = 6.174 kg. Rounding to the nearest kilogram, the mass of the body is 6.0 kg.