Graph It!
On a distance (position) time graph the line has a negative, constant slope. How would we describe this motion?
Going back to start position at a constant speed
Define Inertia
The tendency of an object to want to keep doing what it is already doing.
Does the horizontal speed of an object affect how long it takes for the object to hit the ground? WHY?
No. The vertical component is separate from the horizontal. Gravity pulls everything to the ground at a constant rate.
A roller coaster climbs up a hill at 4m/s and then zips down the hill at 30 m/s. The momentum of the roller coaster is the greatest where?
Mass x Velocity = bottom of the hill
On a distance (position) time graph the line is completely horizontal. How would we describe this motion?
Not moving
What does the slope of a distance v time graph tell us? Be specific
Speed
A ball rolls off a desk at a speed of 3.0 m/s and lands .40 seconds later. How far from the base of the desk does the ball land?
1.2 meters
What is impulse (from your edmentum lessons!!)
change is momentum
10 m/s
During a soccer game, a player exerts a 6 N force using her foot on a soccer ball. What is the reaction force?
6 N from soccer ball to the foot (3rd law)
A projectile was fired with initial velocity 10 m/s horizontally from a cliff. If the horizontal rage of the projectile is 20 m, calculate the height of the cliff.
19.6 meters high
A 3000 kg truck hits a 1500 kg car at a stop sign. The car skidded into traffic 15 m and the truck followed with 10 m. The trucks acceleration with brakes locked -4.5 m/s^2 and the car's is -3 m/s^2.
Describe how you would find total momentum of this system
Must find the momentum of each vehicle prior and add them together. You could also do the same for after the collision
On a velocity time graph the line is completely horizontal. How would you describe this motion?
Moving at a constant velocity
A force of 1 N is the only force exerted on a block and the acceleration of the block is measured. The same force is applied on a second block and the acceleration is three times as large. What can you conclude about the masses of the two blocks?
The second block is 3 times smaller than the first
An object is thrown horizontally off a cliff with an initial velocity of 5.0 m/s. The object strikes the ground 3.0 seconds later.
How far from the base of the cliff will the object strike the ground?
15 meters
What is the formula and units for kinetic energy?
1/2mv^2
Joules
On a velocity time graph between 8 and 10 seconds an objects velocity went from 8 m/s to 0 m/s. What is the distance that was traveled during this interval?
8 meters
A girl walks 24 m at an angle of 45 degrees W of S. How far west of her starting point is she?
About 17 meters west
A ball projected horizontally with an initial velocity of 20 m/s east, off a cliff 100 meters high.
How many seconds does the ball take to reach the ground?
4.5 seconds
A 90 kg halfback runs north and is tackled by a 120 kg opponent running south at 4 m/s. The collision is perfectly inelastic. Just after the tackle, both players move at a velocity of 2 m/s north. Calculate the velocity of the 90 kg player just before the tackle.
10 m/s North