Test Unit 6- Force

Question 1

Part 1 multiple choice

4. When two forces on the same object are equal and opposite these forces are called ____ forces.

Answer 1

Balanced

Unit 6 Concept 3 Notes page 20

Question 2

6. What is the weight of the box in the picture to the right?
   On the left side of the box there is 300N of force and the box itself weighs 25kg.

Answer 2

245 N

Unit 6 concept 3 Notes pg 20

Question 3

8. Consider a watermelon that starts from rest and is dropped straight down from a tall building. Air Resistance can be ignored. Which statement about the watermelons motion is False?

Answer 3

The watermelon falls with a constant velocity.

Unit 6 concept 3 notes page 21

Question 4

13. An object that is falling freely has a constant what?

Answer 4

Acceleration

Unit 6 concept 3 Notes pg.21

Question 5

14. A student drops a feather and at the same time from Mrs. Taylor’s window. If air Resistance was t a factor, what should she observe?

Answer 5

The rock and feather fall at the same rate

Unit 6 concept 3 page 22

Question 6

Part 2 matching

31. A net force acting on an object causes the object to accelerate in the direction of the net force

Answer 6

Newtons 2nd law

Unit 6 concept 3 page 22

Question 7

32. Related to the amount of force needed to change an objects motion…

Answer 7

Momentum

Unit 6 concept 3 page 23

Question 8

38 (b) - what speed will the skydiver eventually reach? What is this speed called?

Answer 8

Maximum speed - terminal velocity
55m/s

Unit 6 concept 3 notes page 22

Question 9

43. A man and his bike are 95kg. His instantaneous speed at one point is 14 m/s. The next time his speed is checked he is going 28 m/s. If the second speed was taken 7 seconds later, what Force must the man have given his bike to change the speed? What was the bicyclist final momentum?

Answer 9

Correction
F= m(a). Pf= m(v) f
F= 95(2). 95(28)
F= 190N. Pf= 2,660 kg * m/s

Unit 6 concept 3 page 24

Question 10

46. In a collision, a 25 kg ball moving at 3 m/s transfers all of its momentum to a 5 kg ball. What is the velocity of the 5kg ball after the collision?

Answer 10

The final answer:

Find momentum of the first ball then find the velocity of the 5kg ball using the momentum. Answer is

V= 15 m/s forward

Unit 6 concept 3 notes page 23