Use the spring scale to pull an object horizontally to move at a constant speed, the number is 0.6N, and then pull it to do a uniform acceleration movement, the reading is 1.8n, 4, and calculate its mass

Use the spring scale to pull an object horizontally to move at a constant speed, the number is 0.6N, and then pull it to do a uniform acceleration movement, the reading is 1.8n, 4, and calculate its mass

Because, with the spring scale horizontal pull an object moving at a constant speed, the indication is 0.6N
Therefore, the sliding friction f = 0.6N
F = 1.8-0.6 = 1.2N
According to f = ma, M = f / a = 1.2 / 0.4 = 3 (kg)
A: slightly