A 60 kg person on in-line skates pushes against a wall with a force of 30 N and recoils. whatwhat acceleration does that person experience

Could someone . i have tried to solve myself but my calculation is off

Asmall object with mass 0.200 kg swings back and forth on the lower end of a light rope that is 3.00 m long. the upper end of the rope is attached to the ceiling. as the object swings through its lowest position, where the rope is vertical, the speed of the object is 5.80 m/s. at this point in the motion, what is the tension in the rope? (use g = 9.80 m/s2.)

If angle "a" is 25°, angle "b" is: a) equal to angle c b) less than angle c c) greater than angle c