Final answer:
To calculate the toy truck's new velocity after being pushed, we use Newton's second law to find the acceleration, then use it to determine the change in velocity, and add it to the initial velocity, resulting in a new velocity of 5.65 m/s.
Step-by-step explanation:
The question involves applying Newton's second law of motion to calculate the new velocity of the toy truck after being pushed by a force. The second law states that the acceleration of an object is directly proportional to the net force acting upon it and inversely proportional to its mass (F = ma). In this case, we can calculate the acceleration of the toy truck using the formula a = F/m, where F is the force applied and m is the mass of the toy truck. Once we have the acceleration, we can calculate the change in velocity (\(\Delta v\)) using the formula \(\Delta v = a * t\), where t is the time duration for which the force is applied. Adding the change in velocity to the initial velocity will give us the new velocity of the toy truck after the push.
To calculate the new velocity, first we find the acceleration:
a = F/m
a = 0.5 N / 0.250 kg
a = 2.0 m/s2
Next, calculate the change in velocity:
\(\Delta v = a * t\)
\(\Delta v = 2.0 m/s2 * 2.2 s\)
\(\Delta v = 4.4 m/s\)
Finally, find the new velocity:
vnew = vinitial + \(\Delta v\)
vnew = 1.25 m/s + 4.4 m/s
vnew = 5.65 m/s
Thus, the toy truck's new velocity when the sister lets go is 5.65 m/s.