4.A roofer pulls a 25.0 kg bundle of shingles up the side of a roof that has a 29.pitch.She applies a force to the shingles,counteracting the 18.5 N of friction,accelerate the shingles at a rate of 0.50 m/s2.Calculate the force she appliedthe shingles.(4)
题目答案请扫描下方二维码查看。