Two-dimensional motion practice

[gary_shuford]

ok i have a test thursday i need help

1.prove an object thrown upwards with a velocity of 20.0 m/s has the same velocity going up past 5.0 meters as it does falling down past 5.0 meters?

[Vf^2=Vi^2 + 2 (-9.81) delta X] ?

2.A car is driving down a road on a snowy day. The car is traveling at a constant 14.0 m/s and is currently 250.0 metersfrom a tree standing by the side of the road. An incicle 4.0m up from the groun on the tree falls onto the car as it passes. how much time elapsed between the time the car was 250.0 m away from the tree and the moment the icicle landed on the car?

i don't know this one at all i tried

3. A tennis ball rolls off the edge of a cruise ship and lands 35.0 m away from the edge of the ship when it hits the watr. If the ships deck is 31.3 meters above the water what was the balls horizontal velocity?

i used delta y = 1/2 g (deltaT)^2

4. A bullet is fired from a gun help parallel to the gorun. The bullets horizontal velocity is 210.0 m/s If the gun is 1.80 meters above the gound, how far will the bullet travel horizontally before hitting the ground.

5.An athlete in the Olympics throws ashot put. The shot put is in the air for 1.89 seconds and lands 6.7 meters away horizontally. Calculate the intial vertical and horizontal components of the shot puts angular velocity. (horizontal velocity = Vi (cos 0), initialy veritcal = Vi(sin 0)

6. A golf ball lands 123.0 m horizontally away from its position after being stuck. If the ball has an angular velocity of 40.0 m./s and is in the air a total of 6.0 seconds calculate the angle at which the ball was launched

can anyone please just give me the formulas to use then i will try to solve them and then yall can help me from there please and thank you gary shuford

 

[hage567]

https://www.physicsforums.com/showthread.php?t=110015

There is more to doing these problems than guessing what formula to use. You need to understand what is going on in the problem. Drawing a diagram helps. You may need to use more than one formula. See what you can do. To figure out what you need, list what you know and what you don't.

 

[m2003]

I would recommend focusing on understanding the concepts behind these problems rather than just memorizing formulas. For the first problem, it is important to understand that the velocity of an object at any point in its motion is determined by its initial velocity and the acceleration acting on it. In this case, the acceleration is due to gravity, which is a constant -9.81 m/s^2. So, when the object reaches a height of 5.0 meters, it will have the same velocity (but in the opposite direction) as it did when it was thrown upwards.

For the second problem, you can use the formula for distance traveled (d = v*t) to find the time it takes for the car to reach the tree. Then, you can use the same formula to find the time it takes for the icicle to fall from the tree to the car.

For the third problem, you can use the formula for horizontal distance traveled (d = v*t) and the given height of the ship's deck to find the time it takes for the ball to travel horizontally. Then, you can use the formula for vertical distance traveled (d = 1/2*g*t^2) to find the ball's initial horizontal velocity.

For the fourth problem, you can use the formula for horizontal distance traveled (d = v*t) and the given initial velocity to find the time it takes for the bullet to hit the ground. Then, you can use the formula for vertical distance traveled (d = 1/2*g*t^2) to find the distance the bullet travels horizontally before hitting the ground.

For the fifth problem, you can use the formula for angular velocity (w = v/r) to find the initial horizontal and vertical components of the shot put's angular velocity.

For the sixth problem, you can use the formula for horizontal distance traveled (d = v*t) and the given time and angular velocity to find the initial velocity of the golf ball. Then, you can use the formula for projectile motion (d = v*t + 1/2*a*t^2) to find the angle at which the ball was launched.

Remember to always include units in your calculations and to check your answers for reasonableness. Good luck on your test!