PHYSICS

Simple Machines

100

1. Machines can change the ___ and ___ of forces. 2. What is another name for the theoretical best mechanical advantage that a system can produce? 3. Third-class levers always increase the ______ of the load.

What is 1. Size and Direction 2. Ideal MA 3. Direction

200

An ideal lever is used to lift a 200 N weight. If a person pushes their side of the lever down 1 m and the weight is lifted up 0.4 m, how hard does the person have to push?

What is 80 N

300

Tommy weighs 100 N and Robert is pushing him up a hill that is 6 m high and 11 m long. 1. What is the IMA? 2. What is the EF is the AMA is 1.5? 3. What is the Work Output?

What is 1. 1.8 2. 67 N 3. 600 J

400

What is A man pushes a 3000 N piano up a 3 m long inclined plane to raise it to his first floor 0.5 meters high. He exerts 900 N of effort force. 1. What is the WO? 2. What is the WI? 3. What is the IMA? 4. What is the AMA? 5. What is the efficiency?

1. 2700 J 2. 1500 J 3. 6 4. 3.3 5. 55%

500

What is You have a simple machine: R = 80 cm (radius of large wheel), r = 8 cm (radius of small axle) and you are lifting a mass of 20kg (connected to axle). 1. What effort force would be required to lift the load if the machine has an efficiency of 75%? 2. What is the AMA? 3. What is the IMA? 4. If the load is lifted 4 m, How much work output did the machine have? 5. How much work would you need to put into the machine? 6. How many turns of the wheel to lift the load 4 m?

1. 27 N 2. 7.5 3. 10 4. 800 J 5. 1067 N 6. 8 times

1D Kinematics and SigFigs

100

Convert 9.9 x 103 kL to cL.

What is 9.9 times 10^8 cL

200

What is 1.83 minutes, YES HE GETS TO EAT IT. Bobby, a lab, rat has 2.0 minutes to go through a maze to get the yummy cheese. He starts off by meandering 100.0 cm down a path at a rate of 2.0 cm/s before stopping, sniffing and deciding to go left or right. It takes him 10.0 seconds to decide to turn right. He then scurries down a 50.0 cm path at a rate of 2.5 cm/s before making a left, speeding up to 3.0 cm/s and racing to the cheese, which is 90.0 cm away. Does he make it before a trap door crashes down, blocking the cheese? How long does it take for him to get there?

What is 1.83 minutes, YES HE GETS TO EAT IT.

300

My friend and I decide to race down a straight stretch of road. We both get in our cars and start from rest. I hold the steering wheel steady, slam on the gas, and my speedometer shows an increase in speed of 10 meters per second every second. 1. What is my acceleration? 2. If I maintain that constant acceleration, how fast will I be going at the end of 10 seconds? 3. How far have I traveled in those 10 seconds?

What is 10.0 m/s, 100. m/s, 500.m

400

At Six Flags Great Adventure Amusement Park in New Jersey, a popular ride known as “Free Fall” carries passengers up to a height of 33.5 m and drops them to the ground inside a small cage. How fast are the passengers going at the bottom of this exhilarating journey? Ignore air resistance.

What is −25.8m /s

500

A pop fly is hit straight up at an initial speed of 40.0 m/s. Ignore air resistance. 1.How long is it in the air if it is caught at the same height from which it was hit? 2.How high is it 2.0 seconds after it is hit? 3.How high does it go? 4.What is its velocity 6.0 seconds after it was hit? 5.How high above its starting point is it 6.0 seconds after it was hit?

What is: 1. 8.00 s 2. 60.0 m 3. 80.0 m 4. -20. m/s 5. 60. meters above the ground

Vectors and Projectiles

100

Rochelle is flying to New York for her big Broadway debut. If the plane heads out of Los Angeles with a velocity of 220.0 m/s in a northeast direction, relative to the ground, and encounters a wind blowing head-on at 45.0 m/s, what is the resultant velocity of the plane, relative to the ground? Draw a picture of the situation.

What is 175.0m/s northeast

200

In her physics lab, Melanie rolls a 10-g marble down a ramp and off the table with a horizontal velocity of 1.2 m/s. The marble falls into a cup placed on the floor 0.51 m from the bottom of the table. Draw a picture of the situation. How high is the table?

What is 0.92 meters

300

What is 2.6 m/s, 0.77s Bert is standing on a ladder picking apples in his grandfather’s orchard. As he pulls each apple off the tree, he tosses it into a basket that sits on the ground 3.0 m below at a horizontal distance of 2.0 m from Bert. Draw a picture of the situation. How fast must Bert throw the apples (horizontally) in order for them to land in the basket? How long will it take?

What is 2.6 m/s, 0.77s

400

What is 1. 8.00 seconds 2. 16.0 seconds 3. 320. meters 4. 960. meters A cannon is fired up from the ground at an angle of 53° from the horizontal, with a velocity of 100.0 m/s. 1. How long will it take for the cannonball to reach its highest point? 2. How long after being fired will the cannonball hit the ground? 3. How high above the ground is the cannonball at its highest point? 4. How far away from the cannon does the cannonball land (horizontal distance)?

What is 1. 8.00 seconds 2. 16.0 seconds 3. 320. meters 4. 960. meters

500

What is Chanel's life?

BAE

Newtons's Laws

100

Does a 2-kilogram rock have twice the mass of a 1-kilogram rock? Twice the inertia? Twice the weight (when weighed in the same location)?

YES for all

200

List Newton's Three laws and his law of universal gravitation.

1. An object in motion tends to stay in motion unless acted upon by an outside force. 2. F= MA 3. For every action, there is an equal and opposite reaction. Law of U Gravitation: Two bodies in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

300

Suppose a pilot announces that the plane is flying at a constant 900. km/h and the thrust of the engines is a constant 80,000. N. a. What is the acceleration of the airplane? b. What is the net force acting on the airplane? c. Are there any other forces that you can identify that are acting on the airplane other than the push of its engines?

1. 0 m/s^2 2. 0 N 3. Gravity, Air resistance and air friction, and the "lift force"

400

A 100. kg skydiver is falling toward the earth. 1. Determine the net force acting on the skydiver. Be sure to mention both the magnitude and the direction of the net force. 2. What is the acceleration of the skydiver at this instant?

1. 580. N downward 2. 5.80 m/s ^2

500

A skydiver jumps from a high-altitude balloon. Answer each of the following questions in a a. As she falls through the air, does her velocity increase, decrease, or stay the same? b. Does air resistance increase, decrease, or stay the same? c. Does the force exerted on her by gravity increase, decrease, or stay the same? d. Does the net force on her increase, decrease, or stay the same? e. Does her acceleration increase, decrease, or stay the same? As she falls from the balloon, her velocity increases at first, then remains constant.

As she falls from the balloon, her velocity increases at first, then remains constant. Air resistance increases (in a direction opposite to her motion) as her speed increases. The force of gravity on her (mg) remains constant. The net force on her decreases as air resistance increases. Her acceleration decreases as the net force decreases.

Momentum and Energy

100

A 500.0-kg pig is standing on the top of a muddy hill on a rainy day. The hill is 100.0 m long with a vertical drop of 30.0 m. The pig slips and begins to slide down the hill. What is the pig’s speed at the bottom of the hill? (Hint: Use the law of conservation of energy, meaning the total of the potential energy and kinetic energy for the pig remains constant, whether the pig is at the top of the hill or at the bottom.)

24.5 m/s

200

A 0.0600-kg tennis ball is traveling at 10.0 m/s toward Venus Williams’s tennis racket. She hits the ball and sends it in the opposite direction with a speed of 36.0 m/s. 1.If the ball is in contact with the racket for 0.0200 seconds, with what average force of impact has Venus hit the ball? 2.What change in momentum does the tennis ball undergo? (Don’t forget that it changes direction.)

1. -138N 2. 2.76 kg times m/s

300

1. 3.75 kg times m/s 2. 3.75 N times s Tiger Woods hits a 0.0500-kg golf ball, giving it a speed of 75.0 m/s. 1. What change in momentum does the golfball undergo? 2. What impulse does Tiger impart to the ball?

1. 3.75 kg times m/s 2. 3.75 N times s

400

Tubby and his twin brother Chubby have a combined mass of 200.0 kg and are zooming along in a 100.0-kg amusement park bumper car at 10.0 m/s. They bump Melinda’s car (also 100.0 kg), which is sitting still. Melinda has a mass of 25.0 kg. After the collision, the twins continue ahead with a speed of 4.12 m/s. How fast is Melinda’s car bumped across the floor? (She moves in the same direction as the twins.)

14.1 m/s

500

In a wild shot, Bo flings a pool ball of mass 0.50 kg off the edge of a 0.68-m-high pool table, and the ball hits the floor with a speed of 6.0 m/s. 1.What is the kinetic energy of the pool ball just before it hits the floor? 2.What is the gravitational potential energy of the pool ball just before it hits the floor? 3.What is the total mechanical energy of the pool ball just before it hits the floor? 4.How much potential energy did the pool ball have (relative to the floor) when it was on the table? 5. Assuming a negligible (too little to notice) amount of mechanical energy was converted to thermal energy (heat) during the pool ball’s fall, how much kinetic energy did the pool ball have when it first left the table? (Hint: Use the Law of Conservation of Energy) 6.How fast was it going when it left the table? (Hint: Use your answer from part e)

What is 1. 9.0 J 2. 0J 3. 9.0 J 4. 3.4 J 5. 5.6 J 6. 4.7 m/s