物理问题。。。英文。。4点前最好。。1) A ball of mass M = 0.320kg is connected by a light but rigid rod of length L = 0.770m to a pivot and held in place with the rod being vertical. A wind exerts a constant force F to the right on the ball. The ball is released from rest,
2019-03-29
物理问题。。。英文。。4点前最好。。
1)
A ball of mass M = 0.320kg is connected by a light but rigid rod of length L = 0.770m to a pivot and held in place with the rod being vertical. A wind exerts a constant
force F to the right on the ball. The ball is released from rest, and the wind makes it swing up to a maximum height Hmax above its starting point before it swings down again. (a) Find Hmax when F = 10.0N; (b) Find the equilibrium height, H for F = 10.0N.
3)
A ring slides along a frictionless rod, and the rod itself is rotating in the horizontal plane about one end of the rod. The position of the ring on the rod measured from the fixed end of the rotating rod is R = 100 t^2 meters, while angle that the rod has rotated in time t is θ = t^3 radians, where the time t is measured in seconds. Find the magnitudes the velocity and acceleration vectors of the ring relative to ground.
4)
A spring is found not ideal and so the force does not obey Hooke’s law. Its restoring force is instead when stretched or compressed, and α = 60.0 N/m, and β = 18.0 N/m^2. The mass of the spring is negligible. (a) Find the potential energy function U(x) of the spring, let U = 0 when x = 0. (b) An object with mass 0.900 kg on a frictionless horizontal surface is attached to this spring and pulled a distance of 1.00 m in +x direction so as to stretch the spring, and then released. What is the speed of the mass when it is at x = 0.5 m and at equilibrium position, respectively.