Question

Question #06e0b

Answer 1

7.5 kg

Explanation:

Friction equation:
`F_r = μN`
So we can calculate normal reaction, N:
`N = F_r/μ = 67/0.91= 73.63` N

Then since there is no acceleration in vertical direction:
`N = mg ⇒ m = N/g = 73.63/9.81= 7.5` kg