3.a golf ball is hit of it’s tee, 200m down the fairway. draw diagrams to show all the forces acting on the ball a) when the ball rests on the tree b)while the club strikes the ball on the tree c) as the ball is in flight

Answers:

3. The diagrams showing the forces acting on the golf ball are in the figure attached. Let’s have a detailed look:

a) Here the ball is under 2 forces:

F1 which is called The Normal force and is perpendicular to the surface of the tee where the ball rests

-F1, related to the gravity force, to the weight of the ball, and has the same magnitude, but the opposite direction (That’s why it has a negative sign).

In this case the sum of the forces is 0

b) Here we have again forces F1 and –F1, but in this very moment the club strikes the ball and we have:

F2, the force of the strike

c) While the ball is in its flight, it is under the following forces:

F1, the force of the lift through the air

-F2, the gravity force

-F3, the force of air resistance, also called drag

F4, the tangencial force of the ball flight

4. Here are the sizes and directions of the resultant forces:

i)Two forces of the same magnitude or size are applied to this block, but in opposite directions (in the x-axis). This is expressed as:

F=-10N+10N=0 The resulting force is zero

ii) Two forces of different size and opposite directions in the y-axis are applied to this block. The sum of the forces is:

F=30N-40N=-10N This means the resulting force is 10N applied downwards

iii) In this case the only force applied to the block is -5N applied downwards

iv) Here there are four forces applied to the block.  

In the y-axis we have to forces of the same size but opposite directions:

F1=10N-10N=0 This means the applied force in the y-axis is zero

In the x-axis we have two forces of different size and opposite directions:

F2=-15N+10N=-5N This means the resulting force is applied to the –x-side

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.