【单选题】An object hanging from a spring (弹簧) will oscillate (震动) up and down. You perform an experiment on a particular mass-spring system, and observe that it oscillates once every 3 seconds. Which of the fo...
【单选题】An object will sink in a liquid if the density of the object is greater than that of the liquid. The mass of a sphere is 9.83 g. If the volume of this sphere is less than __________ cm3 , then the sph...
【单选题】An object of mass 0.50 kg, hanging from a spring with a spring constant of 8.0 N/m, is set into a simple harmonic motion. What is the maximum speed of the object if its maximum displacement is 0.10 m?
【单选题】A constant force of 20 N is applied to an object of mass 8.0 kg at an angle of 25° with the horizontal. What is the work done by this force on the object if it causes a displacement of 2.0 m along the...
【简答题】____ punishment is not a good way to educate children. So no school is allowed to do that.(Mental, Physical)
【单选题】He is _______ scolding his child , which is not a good way to educate him.
【简答题】They have a good _______( educate).