Question

1) The position of an object moving along the x-axis is given by x(t) = 2t^2 - 21t^2 + 100t. At what time is the object moving the slowest?

2) A water balloon is thrown upward from a window 25 m above the ground and hits the ground 3.30 s later. What’s the maximum height above the window that the balloon reaches?

3) A boy throws a rock with an initial velocity of 5.15 m/s at an angle 30° above the horizontal. If air resistance is negligible, how long does it take for the rock to reach the maximum height of its trajectory?

4) . A 3.7-kg object on a frictionless table is subjected to two horizontal forces F1 = 2i +7j and F2 = 2.5i – 5.2j (in newtons). Find the magnitude of acceleration of the object.

5) An applied force of magnitude 123 N pushes a 14-kg block up a frictionless incline that makes an angle of 27° with the horizontal. The applied force is parallel to the surface of the incline. Find the magnitude of acceleration of the block.

6). A 57-kg box is pushed along a horizontal floor at a constant velocity with a 340-N applied force parallel to the floor. Determine the coefficient of kinetic friction between the box and the floor.

Answer 1