From Newton's second law,
F = ma
Where F is the force
m is the mass
and a is the acceleration
Q.1
Here, we are to determine the force acting on the box
m = 3 kg
a = 9 m/s²
Using the formula,
F = ma
F = 3 × 9
F = 27N
Hence, the force acting on the box is 27N
Q.2
Here, we are to determine the acceleration of the car
m = 780 kg
F = 235 N
Using the same formula,
F = ma
235 = 780 × a
a = 235 / 780
a = 0.30 m/s²
Hence, the acceleration of the car is 0.30 m/s²
Q.3
Here, we are to determine the object's mass
a = 5 m/s²
F = 10 N
Using the same formula,
F = ma
10 = m × 5
m = 10 / 5
m = 2 kg
Hence, the object's mass is 2 kg
Learn more on Newton's 2nd law here: https://brainly.com/question/13839211
#SPJ1