Explanation:
The center of gravity is near the grip and does not change during throw. "Throwing through the tip," a popular term of how to throw a javelin, means throwing through the grip or center of gravity. The center of pressure is the aerodynamic force of drag and lift on the javelin.
Acceleration occurs when velocities change.velocity changes either because the speed changes or the direction change.
True would be the Correct answer
Answer:

Explanation:
Given that
At X=0 V=Vo
At X=X1 V=0
As we know that friction force is always try to oppose the motion of an object. It means that it provide acceleration in the negative direction.
We know that



So the friction force on the box
Ff= m x a

Where m is the mass of the box.
Answer:
A velocity time graph shows the change of velocity of an object with respect ot time. If the slope of the graph is increasing in the postive region, it means that the velocity is changing, if the slope is decreasing, it means the the velocity is decreasing, but the object is moving in the same direction (positve direction).
If this slope intersects the graph at x-axis, it means that the body has 0 velocity and has become still. After that, if the line enters in the negative region, it means that its velocity is started to increases again, but the body is movinging in the opposite direction (negative direction)