Answer:
The correct choice is 1 m/s2
Step-by-step explanation:
According to the unitary method if a force of 1 N will cause a mass of 1 kg to have an acceleration of 1 m/s2.
Then obviously force of 7 N applied to a mass of 7 kg will also cause the acceleration of the same rate which will be 7m/s^2
Or
we can use the Newtons law
F = m a
7 = 7 * 1
= 1