Exam 1 Review (questions only)
Chapter 1:
Youtube:
Conversions:
- 60 mph = ___ m/s
Lab/Bonus Quizzes:
- A student walks uphill both ways in the snow to school. The total distance is 8 miles. How far is this in kilometers?
- The state police stop you for traveling at 130 km/h. How fast is this in m/s?
- A professional baseball pitcher can throw a 100 mph fastball. How fast is this in inches per second?
Additional Review:
- A car is traveling at 60 mph. What is it in a) m/s? b) km/hr? c) inches/hour?
- Your house is 144.5x1022 away from school. a) How far is this in feet? b) How far is this in miles? c) How far is this in kilometers?
- Estimate to the nearest 10 how many steps your house is from school in problem #2.
Chapter 2:
Youtube:
- Find acceleration with velocity going from 0 m/s to 20 m/s in 4 seconds.
- If a car goes from initial velocity 30 m/s to 0 m/s in 6 seconds, what is the acceleration?
- If a car is going at a constant velocity of 20 m/s for 10 seconds, how far does it travel?
- If a ball is dropped from 10 m, find its velocity at impact and the time it takes to fall.
- If a ball lands with velocity 20 m/s, find the time it took to fall and the height it was dropped from.
- If a ball is thrown down and 3 seconds later hits the ground at 40 m/s, find its initial velocity and height.
- If a ball is launched upward at 20 m/s, find its maximum height and the time it is up.
- If a ball is thrown upward at 20 m/s, find the time it is coming down, the time it is in air, and its height at 3 seconds.
- If a ball is thrown upward at 20 m/s, find the time it is up, the height at which it is going upward, the time it is in the air, and its velocity as it comes downward (at impact).
Lab/Bonus Quizzes
- 65 mph = ___ m/s
- You are driving at 30 m/s and close your eyes for 2.5 seconds. How far did you travel while your eyes were closed?
- A car can accelerate at 1.6 m/s^2. At this rate, how long does it take to accelerate from 80 to 100 km/hr?
- A ball is dropped from 1000 meters. Ignoring air resistance and using g=9.8 m/s2, calculate the velocity it hits the ground with and the time it takes to fall.
Additional Review:
- A ball is dropped from a building 200m tall. How fast is it going when it hits the ground? How long does it take to hit the ground?
- A ball is dropped from 80m and hits the ground 14s later. Find the acceleration under these circumstances. Was this experiment performed on the Earth?
- A ball is thrown down from the top of a 200m building at 15 m/s. How fast is it going when it hits the ground? How long does it take to fall ½-way (ie. 100m)?
- A ball is dropped from a building 50m tall. How long until it is halfway to the ground? How far above the ground is it when its velocity is ½ the maximum?
- A ball is thrown up at 20 m/s. How fast is it going when it passes the 4th floor (12m above the ground)? How high above the ground after 3 seconds?
- A ball is thrown up at 20 m/s. How high does it go? How long has it been in the air when it is 10m above the ground ‘on the way back down’?
Chapter 3
Youtube:
- You drive off of a 10 m cliff at 20 m/s. Find the time in air along with the horizontal distance.
- You drive off of a ramp to another ramp at a 30 degree angle with an initial velocity of 10 m/s. What is the horizontal distance and the maximum height the cart reaches? Also find the time the cart is going up, and total time in air.
- You drive off of a ramp on a 20 m cliff at an initial velocity of 10 m/s at an angle of 30 degrees. Find the time up and the height you go up (y up). Find horizontal distance and time you go down as well.
Lab/Bonus Quizzes
- In the city, you walk 14 blocks North, 16 blocks East, and 26 blocks South. What is your displacement from your starting point (give both magnitude and direction)? Hint: draw a diagram to visually check your answer!
- A rock is thrown at 20.0 m/s at an angle of 37 degrees to the horizontal. How much later does it hit the ground? Assume the rock is thrown from ground level (i.e. y=0).
- A plane wants to drop supplies onto an island 235m below. If the plane is traveling horizontally at 250 km/h (69.4 m/s ), how far in advance of the island (horizontal distance) must the supplies be dropped?
- James Bond rides off of a building with initial velocity of 25 m/s. The roof is 20 m above the ground below. Calculate how long Mr. Bond is ‘in the air’, how far away from the building he lands, the velocity at impact in both the x & y directions, and how far away from the building he is after 2 seconds have passed.
Additional Review:
- You throw your keys at a 30° angle at 20 m/s of a 10m tall roof. How long until they hit the ground? How far away from the roof do they land?
- A stunt driver wants to jump over a 40m long “lake of fire, sharks, and pointy sticks”. They drive at 20 m/s off 5m tall roof using a homemade 10° ramp. How long were they going ‘up’? How long to come down? Did they ‘make’ the jump?
- Wegman’s offers a new grocery delivery service. The maximum delivery radius is where they throw the groceries at 40 m/s at a 45° angle from the rooftop. If the roof is 20m off the ground, how long are the groceries in the air? What altitude do the groceries reach at their peak (above the ground)? How far away can you live and still get groceries “delivered”?
- A 44 Magnum handgun has a muzzle velocity of 365.9 m/s (1200 ft/s). Standing on a 100m tall cliff, you shoot into the air at an angle of 30°. How far away was the bullet after 5s? What was the altitude of the bullet after 5s? How far away will the bullet impact the ground?
Chapter 4
Youtube
*going through the videos is easier since the diagrams are in the videos with the info!
Lab/Bonus Quizzes
- A net force of 255 Newton’s accelerates an object at 2.2 m/s^2. What is the mass of the object?
- You stand on a bathroom scale in a motionless elevator. When the elevator begins to move, the scale briefly reads 0.75 of your real weight. What is the acceleration of the elevator?
- A 10 kg block rests on a surface where the coefficient of static friction is µs = 0.4. What is the maximum friction force that the surface can produce (i.e. ‘setup’)? What is the minimum horizontal force needed to get the block to start sliding? If a force of 50 N is applied horizontally to the block, determine the resulting acceleration (assume kinetic friction coefficient = static friction coefficient).
Additional Review
- A 10kg box rests on a surface with a coefficient of friction of 0.8. What force must we pull the object with to ‘just’ move it? What force must we push it with to just move it?
- A car skids to a stop in 40m. The officer notes that the car’s mass is 1500kg, and that the coefficient of friction between the tires and the road is approximately 0.5.
- Draw the FBD of the car
- What FORCE caused the car to decelerate and stop?
- Calculate the friction present between the car and the road?
- Using Newton’s 2nd law, calculate the acceleration (i.e. de-celeration) of the car.
- Calculate the initial velocity of the car when it began to skid.
- If the speed limit was 40 mph, does the driver get an award for “overachievement in velocity”?
- Kelly (m=50kg) sits on a 100kg box, resting on the floor. Billy pulls to the LEFT with 200N, Jimmy pulls to the RIGHT with 80N, and Susan pushes DOWN on the box from the left side with 100N at 45°.
- Draw the FBD
- What is the net force in the x direction?
- What is the net force in the y direction?
- If the floor is frictionless, find the box’s acceleration.
- If the coefficient of friction is 0.2, find the box’s acceleration?
- What force must be applied TO THE RIGHT to get it to move?
Chapter 5
Youtube
- A 1000 kg car is driving into a corner with radius 100 meters at velocity 30 m/s. Find friction and coefficient of friction.
- A 1000 kg car is driving into a corner with radius 100 meters at velocity 30 m/s with a coefficient of friction of .4. Find the force of friction to make it, and the velocity needed to drive.
- A 100 kg space cowboy is spinning around and needs to pull 5 g’s. If the radius is 6 m, find the acceleration of the cowboy, the velocity, and the spin rate.
(if unclear:
Lab/Bonus Quizzes
- A horizontal force of 280N is exerted on a 2.0kg object as it is rotated uniformly in a horizontal circle of radius 1.0m. Find the speed of the object.
- Pilots are tested by rotating them in a big horizontal circle at high speeds (you may have seen this on TV). If the pilot feels 7.75 times their own weight (the force they feel=7.75 x weight) when rotating in a circle of radius 10.0m, how fast are they rotating?
- A fictional planet has a mass 2.5 times that of Earth, but the same radius. What is the acceleration due to gravity on the surface of this fictional planet?
Additional Review:
- You swing a 1kg ball in a circle of radius 2m at 10 m/s.
- What force does this take?
- How many g’s does the object experience?
- What velocity must you swing it at to experience 10g’s?
- What would be the force needed to hold it in part c?
- What is the frequency of the object in part c?
- How long does 1 revolution take in part c?
- You have 5,000N of friction available between your tires and the road as you turn on an off-ramp with radius 100m. Your car’s mass is 1200 kg.
- What is the max speed you can travel in the corner?
- How fast if the friction doubles?
- How fast if the friction is reduced to ½?
- How fast if the mass of the car doubles in part (a)?
- How fast if drive a truck that weighs twice as much as the car in part (a)?
- A circus stunt rider enters a 6m radius loop traveling at 10 m/s. If they’re total mass is 100 kg…
- What is the acceleration of the rider?
- How many g’s does the rider feel?
- If the loop will break at a force of 4000N, how fast can the rider travel before breaks?
Chapter 6
Youtube
- If the mass of an object is 1 kg and it is on a spring with k=100 N/m and x = 1, what is the height that the object reaches?
- If a car with a mass of 100 kg is going 10 m/s down a slope of height 10 m, what is its velocity at the bottom of the hill? (point A -> point B)
- If a ball with mass 1 kg falls down at a height of 10 m, find its total energy, energy at ½ way, and its velocity right before it stops moving.
Lab/Bonus Quizzes
- How high will a 0.325kg object go if thrown straight up by someone who does 115J of work on it? Neglect air resistance.
- How much work is required to stop an electron (m= 9.11*10^-31 kg) moving at 1.9*10^6 m/s? Watch your exponents!
- A novice skier, starting from rest, slides down a frictionless 35° slope whose vertical height is 125m. How fast are they going when they reach the bottom?
- A 10 kg object is dropped from 100 m. Using conservation of energy, calculate the velocity the object hits the ground. Check your answer using constant acceleration equations.
Additional Review
- A 10kg ball is sitting at the top of a 20m tall hill.
- What type of energy/energies does the ball have at the top of the hill?
- Calculate the total energy at the top of the hill.
- What type of energy/energies does the ball have halfway down the hill (ignore friction)?
- Calculate the total energy the ball has halfway down the hill.
- Calculate the potential energy the ball has halfway down the hill.
- Calculate the potential spring energy the ball has halfway down the hill.
- Calculate the kinetic energy the ball has halfway down the hill.
- Calculate how fast the ball is traveling halfway down the hill.
- A 10kg ball is dropped from 30m. it lands on a spring with k=1000 N/m.
- What is the total energy the ball has?
- How fast is the ball travelling when it strikes the spring?
- How far does the spring compress in bringing the ball to a stop?
- How much energy is stored in the compressed spring?
- If 200J of energy is lost in launching the ball back up, how high will it now go?
- You eat a few cheeseburgers and consume 1500 Calories (equivalent to about 6,280,000J of energy). If all that energy is put into throwing a 1kg softball into the air, how high will it go?
- How much work must be done to lift a 10kg box to a height of 12m?
- How much energy does this require
- If you want to do this in 6s, what power is required?
- How many horsepower must an engine be to do this for you?