Final answer:
The final velocity of the toy car when a net force of 14 N is used to accelerate it from rest over 4 seconds, with a mass of 7 kg (assuming 'ks' is a typo for 'kg'), is 8 m/s.
Step-by-step explanation:
The student is asking about calculating the final velocity of a toy car given a certain net force, mass, and time of acceleration. To solve this, we use Newton's second law of motion which states that Force (F) = mass (m) × acceleration (a). Given the information, the net force is 14 N and the mass of the car is 7 kg, which appears to be intended as 7 kg since 'ks' is not a standard unit of mass. First, we find the acceleration using the formula a = F/m. Substituting the given values, we get a = 14 N / 7 kg = 2 m/s².
Then, we can use the formula for the final velocity, which is v = u + at, where 'u' is the initial velocity (which is 0 since the car is starting from rest), 'a' is the acceleration, and 't' is the time. Substituting the known values, we get v = 0 + (2 m/s²) × (4 s) = 8 m/s. Therefore, the final velocity of the toy car is 8 m/s.