Auniform ladder is 10 m long and weighs 400 n. it rests with its upper end against a frictionless vertical wall. its lower end rests on the ground and is prevented from slipping by a peg driven into the ground. the ladder makes a 30◦ angle with the horizontal. the magnitude of the force exerted on the peg by the ladder is:

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Anonzero net force acts on a particle and does work. which one of the following statements is true? the kinetic energy of the particle changes, but the speed of the particle does not change. the kinetic energy of the particle does not change, but the speed of the particle does change. the kinetic energy of the particle changes, but the velocity of the particle does not change. the kinetic energy and the speed of the particle change, but the velocity of the particle does not change. the kinetic energy, speed, and velocity of the particle change.

What kind of waves require a medium to travel? question 6 options: light waves mechanical waves all waves need a medium to travel electromagnetic waves