CAN SOMEONE PLEASE HELP ME! Under what situation can an object experience multiple forces, but yet experience no acceleration?

1. An object can experience multiple forces, so long as the net force is zero

2. An object can experience multiple forces, so long as they all act in the same direction

3. An object can experience multiple forces, so long as the mass is proportional

4. An object can experience multiple forces, so long as they are all the same type of force

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

Aballoon is rising vertically upwards at a velocity of 10m/s. when it is at a height of 45m from the ground, a parachute bails out from it. after 3s he opens his parachute and decelerates ata a constant rate 5m/s.when. (a) what was the height of the parachutist above the ground when he opened his parachute? (b)how far is the parachutist from the balloon at t=3s? (c)with what velocity does the parachutist hit the ground? (d)after how long does the parachutist hit the ground after his exist from the balloon?

An electron in an x-ray machine is accelerated through a potential difference of 1.00 × 104 v before it hits the target. what is the kinetic energy of the electron in electron volts?