Answer:
Step-by-step explanation:
y - 2 = 30
y = 32
Simple, first, change 70% into 0.7
thus,
21= 0.7*n
21/0.7=0.7n/0.7
30=n
Thus, your answer, is 30.
If the mower is pulled over a flat horizontal surface, then first get the component of the force in the direction of the mower's displacement:
(120 N) cos(30°) = 60 √3 N ≈ 103.923 N
Then the work done by the boy on the mower over a distance of 12.8 m is
(103.923 N) (12.8 m) ≈ 1330.2 Nm ≈ 1330 J
Well 50% of 30,000 is 15,000
So 10% is 3,000
15,000 - 3,000 = 12,000
So 40% increase is 42,000