Learning Activities #4

REVIEW QUESTIONS


MOMENTUM

1.Which has a greater momentum,a heavy truck at rest to a moving skateboard?
Answer:A moving skateboard

IMPULSE

2.How does impulse differ from force?
Answer:Impulse is the product of the force acting on an object and the time during which it acts while force is any influence that can cause an object to be accelerated measured in neutrons.

4.What is the relationship of the impulse-momentum relationship to Newtons second law?
Answer:The time interval of impulse is buried in the term for acceleration and helps to analyze a variety of circumstances where momentum is change.

DECREASING MOMENTUM OVER ALONG TIME

9.Why might a wine glass survive a fall onto a carpeted floor but not into a concrete floor?
Answer:A wine glass survive a fall unto a carpeted floor not in a concrete because the carpeted floor with give allows for a longer time of impact and therefore a lesser force of impact force over along time to provide the required impulse to reduce the momentum of fall.

BOUNCING

14.Which undergoes the greater change in momentum;
1)A moving object brought to rest 2)the same object projected from rest to he speed it had before ;3)the same moving object brought to rest and then projected backward to its original speed?
Answer:a moving object brought to rest

EXERCISES

2.In terms of impulse and momentum,why are padded dashboard safer in automobiles
Answer:A person sitting inside an automobile pushing against the dashboard has no effect in changing the momentum of the automobile because these forces are are interval forces that forces that act and react within the objects themselves. An outside or external force acting
IN the baseball or automobiles is required for a change in momentum.If no external force is present,then no change in momentum is possible.

8.Why is a punch move forceful with a bare first than with a boxing gloves?
Answer:In both cases the impulses by the boxers jaw reduces the momentum of the punch A) a boxer is moving away when the gloves hits,thereby extending the time of contact.Much of the impulses therefore involves time.B.The boxer is moving into the glove,thereby lessening the time of contact.Much of the impulses therefore involves force.
therefore

Learning Activities#3

REVIEW QUESTIONS

MASS

2.Clearly distinguish among Mass,Weight and Volume?

Answer:Mass is a measure of quantity of matter in an object while weight is the force upon an object due to gravity and these volume is the space occupied by the object.

5.What kind of path would the planets follow if suddenly no force acted on them?

Answer:Straight line path off into space

When acceleration is Zero-Equilibrium

13. Consider a book that weighs 15N at rest on a flat table.How many newtons of support force does the table provide?What is the net force on the book in this case?

Answer:15n of support force the table provide.The table pushes up on the book with as much force as downward force of gravity on the book, so the net force on the book is zero.

20.What is meant by free fall?

Answer:Free fall is that when there is only force of gravity that acts, on which is the weight that is when air resistance and the like are negligible.

HOME PROJECTS

2.Drop a sheet of paper and a coin at the same time.Which reaches the ground first?Why?Now crumple the paper into a small tight wad and again drop it with the coin.Explain the difference observed.Will they fall together if dropped from a second-,third-, or fourth-story window?Try it and explain your observations.

Answer:When we drop a sheet of paper and a coin at the same time,the coin dropped first in all move we done from first to fourth,then on the second move which we crumpled paper they fall together until the fourth story window because on the first move there is a present of air resistance which is on the paper we call it as free fall that's why a coin dropped first while on the second move there is none air present that's the reason why it dropped together.

5.The net force acting on an an object and the resulting net force are always in the same direction .You can demonstrate this with a spool.If the spool is pulled horizontally to the right, in which direction will it roll?

Learning Activities#2

REVIEW QUESTIONS

COPERNICUS AND THE MOVING EARTH

3. Contrast the relationship between the earth and sun as seen by Aristotle and by Copernicus?

Answer: According to Copernicus and Aristotle from their astronomical observations that the earth travelled around the sun.

GALILEO AND THE LEANING TOWER

4. What did Galileo discover in his legendary experiment on the leaning tower?

Answer: Galileo discovered that a stone twice as heavy as another did not fall twice as fast, except for the small effect of air resistance, he found that objects of various weights, when released at the same time, feel together and hit the ground at the same time.

GALILEO's INCLINED PLANES

6. What does it mean to say an object has inertia?Give example.

Answer:A property of a moving object to continue moving,it means it has inertia.

SPEED

10. What is the average speed of a horse that gallops a distance of 15 km in a time of 3o min.?

Answer: s=d/t
s=15/3o
s=o.5

VELOCITY

12. Distinguish between speed and velocity?

Answer: Speed is a combination of distance and time while velocity describes speed and the direction of motion.

ACCELERATION

15. Distinguish between velocity and acceleration?

Answer: When we say velocity there is speed and the direction of motion while acceleration we can change velocity of something by changing its speed by changing its direction or by changing both its speed and its direction or the rate of change in velocity.

16. What is the acceleration of a car that increases its velocity from 0-100 km/h in 10 s?

Answer: A=100 km/h
----------------

10 s

A= 10 km/h/s

HOW FAR

27. What is a distance fallen for a freely falling object 5 s after being dropped from a rest position?What is its 6 s after?

Answer: v=gt g=(10 m/s) (6 s) v=gt
v= 50(5) g= 60 m/s2 v= (60 m/s2) (6 s)
v= 250 m/s v= 360 m/s

EXERCISES

4. One airplane travels due north at 300 km/h while another travels due south at 300 km/h? Are their speeds the same? Are their velocities the same? Explain.

Answer: Yes, they have the same speed but they have opposite velocities.
Because it moves it in an opposite direction.

8. If you were standing in an enclosed car moving at constant velocity, would you have to lean in some special way to compensate for the cars motion? What if the car where moving with a unchanging acceleration? Explain.

Answer:No, Because the car was moving with unchanging acceleration you can't easily stop the car because of its speed.