Question

please answer number 3 and 4.

3. A food shipper pushes a wood crate (total mass m 15 kg) across a concrete floor with constant force F of magnitude 45 N. In a straight line displacement of magnitude d-0.8 m, the speed of the crate decreases from vo-0.8 m/s to v-0.3 m/s. (a) How much work is done by the force F? (b) What is the increase AE, in the thermal energy of the crate and floor? 4·Three particles of masses mi = 1.5kg, m2-3.0kg and m3-3.5kg form an equilateral triangle of edge length a-150cm. Where is the center of mass of this system?

Answer 1

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