Projectile Motion Created by Craig Smiley (Harrison HS, West Lafayette, IN) Supported by grant PHY-0851826 from the National Science Foundation and by Purdue University

Horizontal Launch Which one had a greater initial velocity just in the vertical direction? The dropped one The thrown one Both were equal to zero Both were the same, but not zero

Horizontal Launch Which ball is going faster just in the vertical direction right before hitting, the ball that was thrown horizontally or the ball that was dropped? Ignore air resistance. The one that was thrown The one that was dropped They have the same vertical speed Impossible to tell with given info.

Horizontal Launch If you threw a ball horizontally from a 3rd story window and a friend dropped a ball from a window above you, which ball would hit the ground first? The one that was thrown The one that was dropped They will hit at same time It depends on what floor your friend is on

Horizontal Launch A car drives horizontally off a cliff into the ocean. What happens to the horizontal velocity during its flight? Ignore air-resistance It is the same as the speed it had when it first went off the cliff It is decreasing It is increasing There is no more horizontal velocity once it leaves the cliff

Horizontal Launch If a car drives straight off a cliff. During its flight, starting right as it leaves the cliff, to right before it plunges into the ocean, what values are true? Its final vertical velocity (vfy) = 0 Its initial vertical velocity (viy) = 0 Its final horizontal velocity (vfx) = 0 None of these Two of these (A-C)

Launch at Angle from Ground to Ground A cannon ball was shot up out of a cannon at an angle. At the highest point, what do you know is true? The overall velocity = 0 It is moving the slowest, but NOT = 0 It is moving the same speed as it did coming out of the cannon Its thinking “oh, this is going to hurt ”

Thrown at Angle If you threw a ball up at an angle off of a building and dropped one at the same time from the same height, which one would hit the ground first? Ignore air resistance. The one that was thrown The one that was dropped They will hit at same time Impossible to tell with given info.

Horizontal Launch Which is going faster overall during the flight (or right before they hit), the ball that was thrown horizontally or the ball that was dropped? Ignore air-resistance. The one that was thrown The one that was dropped They are going the same speed Impossible to tell with given info.

Horizontal Launch If you shot a bullet out of a gun horizontally and dropped a bullet at the same time from the same height as the barrel of the gun, which bullet would hit the ground first? Ignore air resistance and the curvature of the Earth. The one that was shot The one that was dropped They will hit at the same time Depends on how fast the bullet is going

Horizontal Launch A bullet is fired horizontally from a rifle. (Ignore air resistance) The initial speed of the bullet when it leaves the gun barrel is vo. Which of the following three statements is false: During its entire flight, the minimum speed of the bullet is vo. The acceleration of the bullet is constant during its flight. The time it takes for the bullet to hit the ground increases as vo is increased. All of the above statements are true!

Launch at Angle from Ground to Ground An arrow is shot out of a bow at 40m/s at an angle of 60°. What is its overall speed at the highest point? 40 m/s 34.6 m/s 20 m/s 10 m/s 0 m/s

Launch at Angle from Ground to Ground A golf ball is struck so that is it initially going 70m/s at 30°. What is its final vertical velocity if it lands at the same height it was struck from? Ignore air resistance -70 m/s -60.6 m/s -35 m/s -10 m/s 0 m/s

Launch at Angle from Ground to Ground A soccer ball is kicked so that it leaves the ground going 30m/s at 30°. What is its overall speed when it’s hitting the ground at the same height? 30 m/s 26 m/s 15 m/s 10 m/s 0 m/s

Range An arrow is shot into the air at an angle of 50° and lands on a target that is at the same level at which the arrow was shot. Another arrow will also hit the target if it is shot with the same speed at which angle? 40° 45° 55° 60° None of these

Complimentary Angles Two guns are fired from ground level at equal speeds but different angles. One is fired at an angle of 30° and the other at 60°. Which bullet will hit the ground first? The one shot at 30° The one shot at 60° Both will hit at the same time It is impossible to tell with given info

Launched Vertically Ball 1 is launched at 10m/s straight up, and Ball 2 is launched at 20m/s also straight up. If both are launched at the same time, from the same height, and both land at the same height at which they were launched, how do their max heights compare? AND how do their times in the air compare? Max Height Time in Air A. 1 = 2 1 = 2 B. 1 < 2 1 = 2 C. 1 < 2 1 < 2 D. 1 = 2 1 < 2 E. Can’t be determined

Windy Day You are playing goalie for your soccer team on a windy day. You want the to drop-kick the ball as far as you can, but the wind is blowing against the way you want to kick. What angle should you kick the ball in order to create the greatest range? More than 45° 45° Less than 45°