Science Final Test

A 7.26kg bowling ball (16 pounds) is at rest at the end of a bowling lane. Use this information to answer the following questions. Following your push the ball rolls down the lane at 4.2m/s. What is the net force on the ball as it rolls down the lane at the constant speed?

0N

What is the net force if you push a cart to the right with 5N of force and a friend pushes the cart to the left with 5N of force?

0N

A 7.26kg bowling ball (16 pounds) is at rest at the end of a bowling lane. Use this information to answer the following questions. . What is the net force acting on the ball?

0N if its at rest

A 2-kg object is moving horizontally with a speed of 4 m/s. How much net force is required to keep the object moving at this speed and in this direction? Explain.

0N, it will maintain its speed of 4m/s if no outside forces act on it.

A 7.26kg bowling ball (16 pounds) is at rest at the end of a bowling lane. Use this information to answer the following questions. CHALLENGE: How long did you push the ball in this situation?

1.5 seconds

What is the acceleration of a 6.4 kilogram bowling ball if a force of 12 N is applied to it?

1.875 m/s/s

What is the net force if you start to pull instead of pushing in #6?

10N

What is the rate of acceleration of a 2,000-kilogram truck if a force of 4,200 N is used to make it start moving forward?

2.1 m/s/s

A 7.26kg bowling ball (16 pounds) is at rest at the end of a bowling lane. Use this information to answer the following questions. What is the acceleration caused by your push on the ball?

20.5 N/7.26 kg = 2.82m/s/s

A 7.26kg bowling ball (16 pounds) is at rest at the end of a bowling lane. Use this information to answer the following questions. b. You push the ball with a force of 22.8N which induces a -2.3N frictional force. What is the net force while you push the ball?

22.8N - 2.3N = 20.5N

A Cadillac Escalade has a mass of 2 569.6 kg, if it accelerates at 4.65m/s2 what is the net force on the car?

2569.6 x 4.65m/s/s= 11948.64N

A small child has a wagon with a mass of 10 kilograms. The child pulls on the wagon with a force of 2 newtons. What is the acceleration of the wagon?

2N/ 10 kg = 2m/s/s

You know the mass of an object and the force applied to the object to make it move. Which of Newton's laws of motion will help you calculate the acceleration of the object?

2nd law, Law of acceleration

How many newtons of force are represented by the following amount: 3 kg·m/sec2 ? Justify your answer.

3N, ass of 3kg x 1m/s/s

Your shopping cart has a mass of 65 kilograms. In order to accelerate the shopping cart down an aisle at 0.3 m/sec2 , what force would you need to use or apply to the cart?

65 kg x 0.3 m/s/s= 19.5N

What is the mass of an object that requires a force of 30 N to accelerate at a rate of 5 m/sec2 ?

6kg

How much force is needed to accelerate a 68 kilogram-skier at a rate of 1.2 m/sec2 ?

81.6 N

What is the acceleration of a 0.30 kilogram ball that is hit with a force of 25 N?

83.33 m/s/s

What is the mass of an object that needs a force of 4 500 N to accelerate it at a rate of 5 m/sec2

900 kg

What is the force on a 1 000 kilogram-elevator that is falling freely under the acceleration of gravity only (9.8m/s2 )?

9800 N

Force is measured in newtons. A newton is based on base units in the metric system. What is a newton equal to in terms of units of mass and acceleration

A newton is a equal to the mass in kg x acceleration of object is m/s/s

If you double the force of an object what happens to the acceleration?

Acceleration doubles

If you increase the force on an object what happens to the acceleration?

Acceleration is directly proportional to mass, in this example it will accelerate as fast or faster depending on the decreased mass.

If you use the same force on a less massive object what happens to the acceleration?

Acceleration is inversely proportional to mass, in this example it will accelerate as fast of faster depending on the decreased mass

If you double the mass of an object what happens to the acceleration

Accelerations is halved

Forces come in pairs. What are these pairs called?

Action and reaction forces

What causes an object to slowdown or speed-up?

An external force acting on an object

Restate Newton's first law in terms of acceleration.

An object not accelerating will maintain its velocity if its in motion or stay still if its at rest

What is required to cause acceleration?

An unbalanced force

. Imagine a place in the cosmos far from all gravitational and frictional influences. Suppose that you visit that place (just suppose) and throw a rock. What will the rock do? Why?

Continuously move in the direction you throw it. Newton's first law.

If you double the mass of an object while leaving the net force unchanged what is the result on the acceleration?

Doubling the mass will halve the acceleration

If you double the net force on an object what is the result on the acceleration?

Doubling the net force will double the acceleration

CHALLENGE: What is the mass of an object that needs a force of 6 600 N to increase its speed from rest to 107 m/s in 2.3 seconds?

First find the acceleration using the acceleration formula: 107 m/s 2.4 seconds= 46.5 m/s/s Now find the mass by divining force, 6,800/46.5 m/s/s= 141.9kg

True or False: Once the object hits the water, the forces are balanced and the object will stop. Support your answer with reasoning.

Forces are balanced in the pool, but the box will continue to sink

If an object is not accelerating what can you determine about the sum of all the forces on the object?

Forces are balanced.

Why doesn't a ball roll on forever after being kicked at a soccer game?

Frictional forces, air resistance all working to resist motion

If the force are balanced what is the resulting acceleration

If forces are balanced, there's no acceleration

An object's resistance to change in motion is dependent solely on what quantity?

Inertia

When Jane drives to work, she always places her purse on the passenger's seat. By the time she gets to work, her purse has fallen on the floor in front of the passenger seat. One day, she asks you to explain why this happens in terms of physics. What do you say?

Law of interia, every time she stops

Inertia is the resistance to change in motion so inertia depends solely on what?

Mass

What two variables is acceleration dependent on? What is the relationship between these variables and acceleration? (i.e. if you increase one variable what happens to the acceleration?)

Mass and force, more force equals greater acceleration, more mass equals less acceleration

If the net force on an object is in a negative direction, what will the direction of the resulting acceleration be?

Resulting acceleration will be in negative direction

Which law is associated with inertia?

The first law

You are waiting in line to use the diving board at your local pool. While watching people dive into the pool from the board, you realize that using a diving board to spring into the air before a dive is a good example of Newton's third law of motion. Explain how a diving board illustrates Newton's third law of motion

The force you pin into the diving board gets returned back to you and helps you gain a higher jump off the board

Ben Tooclose is being chased through the woods by a bull moose which he was attempting to photograph. The enormous mass of the bull moose is extremely intimidating. Yet, if Ben makes a zigzag pattern through the woods, he will be able to use the large mass of the moose to his own advantage. Explain this in terms of inertia and Newton's first law of motion.

The more massive moose has more inertia, making it more difficult to zigzag than a smaller less massive person with less mass

Which law explains why when you bump into something you fall backwards?

The third law, action/ reaction

2. Supposing you were in space in a weightless environment, would it require a force to set an object in motion? Explain.

Yes, to change the state of motion of an object requires force

You dribble a basketball while walking on a basketball court. List and describe at least 3 pairs of action-reaction forces in this situation.

ball/hand, ball/floor, feet/floor while walking

Are forces result because of _ between objects

interaction

Which law states force is dependent on the mass and acceleration of an object

the second law of motion.

What law is known as the law of action- reaction

the third law