Answer:
m=146.277kg which is rounded to 146kg
Step-by-step explanation:
Remember that F=ma
But F represents not 250N, but 250cos(35)N since the force is being pulled above the horizontal.
So 250cos(35)=204.7880111 approximately, and since a=1.4m/s^2, we have 204.7880111=m(1.4m/s^2). Then we divide both sides by the acceleration to get the mass. So m=146.2771508kg which the nearest number is 146kg
Mass is always in kg, unless stated otherwise.