A 10-kg box sitting on a horizontal surface is pulled by a 5.0-N force. A 3.0-N friction force retards the motion. What is the acceleration of the object?
0.50 m/s².
0.30 m/s².
5.0 m/s².
0.20 m/s².
A student pulls a box of books on a smooth horizontal floor with a force of 100 N in a direction of 370 above the horizontal. If the mass of the box and the books is 40.0 kg, what is the acceleration of the box?
3.3 m/s².
1.9 m/s².
2.0 m/s².
1.5 m/s².
A ripe mango falls from a tree 32 m tall. If its initial velocity is zero, the time it takes to reach the ground is:
64.0 s.
1.8 s.
2.5 s.
6.4 s.
A person of weight 480 N stands on a scale in an elevator. What will the scale be reading when the elevator is accelerating downward at 4.00 m/s²?
196 N.
284 N.
676 N.
480 N.
