Honors PhysicsDisplacement through Launch at an Angle
September 14, 2011 A person initially at point P in the illustration stays there a moment then moves along the axis to Q and stays there a moment. She then runs quickly to R, stays there a moment, and then strolls slowly back to P. Which of the position vs. time graphs below correctly represents this motion?
September 27, 2011 A car moves along the x axis. What is the sign of the car’s acceleration if it is moving in the positive x direction with increasing speed? decreasing speed? What is the sign of the acceleration if the car moves in the negative direction with increasing speed? decreasing speed?
Average Acceleration A car accelerates along a straight road as illustrated below. What is the magnitude of its average acceleration? +15km/h/s
Average Acceleration An automobile is moving to the east along a straight highway. Then the driver puts on the brakes. Using the information from the graphic, what was the car’s average acceleration during braking? 2.0m/s2 West
Average Acceleration A car moves to the west as show in the diagram. What is the car’s average acceleration? 2.0m/s2 East
Runway Design You are designing an airport for small planes. One kind of airplane that might se this airfield must reach a speed before takeoff of at least 27.8m/s, and can accelerate at 2.00m/s2 . What is the minimum length that the runway must be? 193m
Acceleration of a car How long does it take a car to cross a 30.0m wide intersection after the light turns green, if the car accelerates from rest at a constant 2.00m/s2? 5.48s
Taking the baby for a jog A person pushing a jogging stroller at 1.00m/s starts uniformly accelerating at a rate of 0.500m/s2. What is the velocity of the stroller after it has traveled 4.75m? 2.40m/s
Free Fall Time (s) Velocity (m/s) 0 0 1 10 2 20 3 30 … … t 10t
Free Fall What is the speed of a falling rock 3.5s after being dropped from rest? 34.3m/s down 6s after being dropped? 58.9m/s down 10s? 98.1m/s down
Tower Drop Suppose that a ball is dropped from a tower 70.0m high. How far will the ball have fallen after 1.00s? 4.90m down 2.00s? 19.6m down 3.00s? 44.1m down
Tower Throw Down! Suppose the ball is instead thrown downward with an initial velocity of 3.00m/s. How far will it have fallen after 1.00s? 7.90m down after 2.00s? 25.6m down Compare the speed of the dropped ball with the speed of the thrown ball after 2.00s have passed. 19.6m/s vs. 22.6m/s
Eww – Throw Up! A person throws a ball up into the air with an initial velocity of 15.0m/s. Calculate (a) how high it goes and (b) how long it is in the air before it comes back to his hand. (a) 11.5m up (b) 3.06s Find the time at which the ball in the question above is 8.00m high? (Quadratic) 0.69s (on the way up) and 2.37s (on the way down)
Crosswind Landing A pilot is flying a plane due south to warmer weather at 275km/h as a wind carries him due west at 35km/h. Find the magnitude and direction of the plane’s resultant velocity.
Crosswind Landing A pilot needs to approach for a landing at 250km/h 30˚ W of S with the presence of wind blowing due West. What is the velocity of the wind? What is the velocity with which he must fly the plane?
The Race Two balls are launched simultaneously from the same height. Ball A is released from rest, and drops straight down. Ball B is given an initial horizontal velocity. Which ball hits the ground first? Ball A Ball B Both balls hit the ground at the same time
The Ballistics Cart A ballistic cart is a cart that can shoot a ball vertically and (maybe) catch it again. With the cart rolling at constant speed when it shoots the ball, where will the ball land? In the cart Behind the cart Ahead of the cart
What do you think? Consider the situation depicted here. A gun is accurately aimed at a dangerous criminal hanging from the gutter of a building. The target is well within the gun’s range, but the instant the gun is fired and the bullet moves with a speed of v0 , the criminal lets go and drops to the ground. What happens? The bullet hits the criminal regardless of the value of v0 . hits the criminal only if v0 is large enough. misses the criminal.
October 18, 2011 At which point or points on the graph below is… Vx = 0m/s the vertical velocity zero. the horizontal velocity nonzero. the vertical acceleration zero. the horizontal acceleration zero. the vertical velocity positive. the vertical acceleration nonzero.
Horizontal Launch ∆t ∆x vx vy ∆y 0s 0m 20m/s 0 0m 1s 20m 20m/s -9.8m/s -4.9m 2s 40m 20m/s -19.6m/s -19.6m 3s 60m 20m/s -29.4m/s -44.1m An object is launched horizontally at 20m/s off a cliff. What is its velocity after 1.0s? Where is it at 1.0s? If the cliff is 30m tall, how high from the base of the cliff did the object land?
Give it a shot! A person standing at the edge of a seaside cliff kicks a stone over the edge with a speed of 18m/s. The cliff is 52 m above the water’s surface. How long does it take for the stone to fall to the water? With what speed does it strike the water?
October 19, 2011 I am working on the bullet question. We will discuss it Friday! A ball rolls off of a 12m tall cliff and lands 14m from the base. With what velocity was it rolling? 8.97m/s
Tricky, tricky! A spy in a speed boat is being chased down a river by government officials in a faster craft. Just as the officials’ boat pulls up next to the spy’s boat, both boats reach the edge of a 5.0 m waterfall. If the spy’s speed is 15 m/s and the officials’ speed is 26 m/s, how far apart will the two vessels be when they land below the waterfall?
Oh OH! Four dozen exotic animals, including lions, tigers, bears, wolves, cheetahs, and giraffes, are currently on the loose in Ohio. A zoologist standing on a cliff spots a monkey hanging from tree 10.5m tall, 140m away. He takes aim at the monkey with a tranquilizer gun. The barrel of the gun is horizontal. If the tranquilizer dart travels at 70.0m/s. If the monkey lets go of the tree at the same time the dart is fired, what height above the ground will the monkey be at when he is hit by the dart?
Launch at an Angle A human cannonball is launched at 20m/s at 35˚ above horizontal. Assume ground-to-ground trajectory. Neglecting air resistance… Find the maximum height that he reaches. How long is he in the air? How far from the cannon does he land? What is his velocity at 1.0s? What is his minimum velocity? What is his velocity when he lands?