Final answer:
The net force needed to lift a full grocery sack with a weight of 210 N and accelerate it upward at 1.5 m/s² is 32.15 N.
Step-by-step explanation:
In order to calculate the net force needed to accelerate the grocery sack upward, 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.
Given that the weight of the grocery sack is 210 N and the desired acceleration is 1.5 m/s², we can calculate the net force using the formula:
Net force (Fnet) = mass (m) x acceleration (a)
To find the mass, we can use the formula:
Weight (W) = mass (m) x gravitational acceleration (g)
Since the acceleration due to gravity is approximately 9.8 m/s², we can rearrange the formula to find the mass:
Mass (m) = Weight (W) / gravitational acceleration (g)
Substituting the values into the equations, we get:
Mass (m) = 210 N / 9.8 m/s² = 21.43 kg
Net force (Fnet) = 21.43 kg x 1.5 m/s² = 32.15 N
Therefore, the net force needed to lift the full grocery sack and accelerate it upward at 1.5 m/s² is 32.15 N.