How Do You Calculate Time and Speed in These Physics Problems?

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In summary, the first question involves determining the time a water-filled balloon takes to reach the ground from a height of 5.53 m without knowing the initial velocity. The second question involves finding the initial speed of a second arrow shot vertically upwards 2 seconds after the first arrow, which has an initial speed of 25.6 m/s. The third question involves determining the distance from the top of a cliff where two balls, one dropped from rest and the other thrown upwards with the same initial speed, cross paths. The fourth question asks how much further a giant tortoise, with an average speed of 0.0193 m/s, would have gone compared to a three-toed sloth, which moves at an average speed of
  • #1
hyen84
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Physics questions...

1.) From her bedroom window a girl drops a water-filled balloon to the ground, 5.53 m below. If the balloon is released from rest, how long is it in the air? ** they didn't give me any velocity, so i don't know waht to do **

2.) Two arrows are shot vertically upward. The second arrow is shot after the first one, but while the first is still on its way up. The initial speeds are such that both arrows reach their maximum heights at the same instant, although these heights are different. Suppose that the initial speed of the first arrow is 25.6 m/s and that the second arrow is fired 2 s after the first. Determine the initial speed of the second arrow. ** ím lost on this one**

3.) A ball is dropped from rest from the top of a cliff that is 27.6 m high. From ground level, a second ball is thrown straight upward at the same instant that the first ball is dropped. The initial speed of the second ball is exactly the same as that with which the first ball eventually hits the ground. In the absence of air resistance, the motions of the balls are just the reverse of each other. Determine how far below the top of the cliff the balls cross paths. ** totally lost***

4.) The three-toed sloth is the slowest moving land mammal. Assume that on the ground the sloth moves at an average speed of 0.013 m/s, considerably slower than the giant tortoise, which walks at 0.0193 m/s. After 20 minutes of walking, how much further would the tortoise have gone relative to the sloth?

** please help this homework is due tomorrow..thank you.. i'll buy you guys ice cream for helping me with the questions...
 
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  • #2
Read in your textbook about the acceleration due to gravity.

This will help you on the first, second and third questions.

The fourth question is simply determine how far each animal can travel in the allotted time and the difference between these two numbers. (Read in your textbook about average speed and average velocity.)
 
  • #3
[tex]v(t) = v_0 + \frac{1}{2} a t^2[/tex]
i think this is the equation to use.
 

What is the equation used to calculate initial speed in physics?

The equation used to calculate initial speed is v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time.

How do I calculate the initial height of an object in a physics problem?

The initial height of an object can be calculated using the equation h = ut + (1/2)at^2, where h is the initial height, u is the initial velocity, a is the acceleration, and t is the time.

What is the difference between initial speed and initial velocity?

Initial speed is the magnitude of the initial velocity, while initial velocity includes both the magnitude and direction of the initial motion.

Can I use the same equation to calculate initial speed and initial height?

No, the equations for initial speed and initial height are different. However, they both involve the initial velocity and acceleration of an object.

How do I solve for initial speed or initial height if I am given the final velocity instead?

You can use the equation v^2 = u^2 + 2ah to solve for initial speed, or the equation v = u + at to solve for initial height. Rearrange the equations to isolate the variable you are solving for.

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