Answer:
Force = 8.0 k g m / s
Explanation:
Force = mass x acceleration
Mass = 4.0 k g Acceleration = 2.0 m / s 2
Hence,force = ( 4.0 x 2.0 ) k g m / s 2 = 8.0 k g m / s 2
Answer:
0.031 W
Explanation:
The power used is equal to the rate of work done:

where
P is the power
W is the work done
t is the time taken to do the work W
In this problem, we have:
W = 900 J is the work done by the motor
t = 8 h is the time taken
We have to convert the time into SI units; keeping in mind that
1 hour = 3600 s
We have

And therefore, the power used is

Choice ' C ' is a true statement.
The other choices aren't.