Force test

Question 1

A 500 N force is applied to a 25 m/s2 object. What is the mass?

Answer 1

20 kg

Forgot to put kg instead of m/s

Question 2

2.)When 2 forces on the same object are equal and opposite, these forces are called …..

Answer 2

Balanced forces

Concept 3 pg 1

Question 3

6.) What is the weight of the box in the picture?
300 N
———> 25 kg

Answer 3

245 N

Concept 3 pg 4

Question 4

8.) Consider a watermelon that starts from rest and is dropped straight down from a tall building. Air resistance can be ignored. Which statement is false. (A) the watermelon falls with a constant velocity (B) the watermelon has a positive acceleration (C) after 2 seconds, its velocity is 19.6 m/s

Answer 4

A.
The watermelon actually does not fall at a constant velocity
Concept 3 pg 3

Question 5

12.) What best describes how a swimmer moves through the water?

Answer 5

The swimmer pushes backwards on the water and the water pushes with an equal but opposite force back on the swimmer

Question 6

13.) an object that is falling freely has a constant What?

Answer 6

Acceleration

Concept 3 pg 3

Question 7

15.) if the card were quickly pulled off the cup what property would explain why the coin falls into the cup rather than moving with the card

Answer 7

Inertia

Concept 3 pg 1

Question 8

18.)If the same force is applied to each of the balls: tennis ball, a foam ball, a baseball, a bowling ball, which one will have the least acceleration

Answer 8

Bowling ball

Question 9

19.) An object in motion with no unbalanced forces acting on it will

Answer 9

Continue to move in its path at a constant speed

Question 10

21.)The relationship among mass, force, and acceleration is explained by

Answer 10

Newton’s 2nd law

Concept 3 pg 3

Question 11

25.) An object will move at a constant velocity unless an unbalanced force acts upon it

Answer 11

Newton’s 1st law

Concept 3 of 1

Question 12

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

Answer 12

Newton’s 2nd law

Concept 3 pg 3

Question 13

32.) Related to the amount of force needed to change an object’s motion

Answer 13

Momentum

Concept 3 pg 4

Question 14

33.) Why does someone not wearing a seatbelt in a car fly forward when the car stops suddenly?

Answer 14

Because objects in motion resist a change in motion due to inertia
Newton’s 1st law

Concept 3 pg 1

Question 15

34.) why does it take more effort to make a bowling ball accelerate 25 m/s2 then to make a tennis ball accelerate 25 m/s2?

Answer 15

The bowling ball has more mass and needs a greater force to accelerate it. Newton’s 2nd Law

Concept 3 pg 3

Question 16

38.) Why does Terminal Velocity occur when the skydiver skydives?

Answer 16

Gravity and air resistance become balanced, and humans have a constant velocity when they fall

Concept 3 pg 3

Question 17

A 2 N and an 8 N force pull an object to the right and a 4 N force pulls on the object to the left. If the object has a mass of 0.5 kg what is its acceleration

Answer 17

28 m/s2

Forgot to put m/s2

Question 18

If a 53 kg boulder falls off a cliff, what is the force with which it will hit the ground

Answer 18

519.4 N

Question 19

43.) A man and his bike are 95 kg. 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 seven seconds later, what force must a man have given his bike to change the speed? What was the bicyclist’s final momentum?

Answer 19

F = ma              P = mv
F = 95(2)        P = 95(28)
F = 140N         P = 2,600 kg*m/s

Question 20

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 5 kg ball after the collision?

Answer 20

15 m/s forwards

Forgot forwards