Ball dropped from building - find speed and kinetic energy

In summary, a 0.50kg mass is dropped from the top of a 20m tall building and the speed of the ball immediately before hitting the sidewalk can be calculated using the equation vf= (2*9.8*20) square root of this answer. For part b, the KE of the ball half way down can be calculated using the equation vf= 2*9.8*10 and square root of this, resulting in a speed of 14.
  • #1
NewJersey
35
0
An 0.50kg mass is droped from the top of a 20m tall building. Immediately before hitting the sidewalk

a) the speed of the ball is ?
b) The KE of the ball half way down will be


Help??
 
Physics news on Phys.org
  • #2
What's being conserved here, and what equation should you use? Any thoughts?
 
  • #3
Basically right now I am at this point
vf= (2*9.8* 20) the sqaure root of this answer .

Would that tell me the final speed
 
  • #4
Yes, that is correct.
 
  • #5
So for part b

vf= 2*9.8*10 and the sqaure root of this
= 14

Is this part right.
 
  • #6
Well, that is the speed that you would plug into the equation for kinetic energy, but yes, you are correct.
 

1. How is the speed of a ball dropped from a building calculated?

The speed of a ball dropped from a building can be calculated using the equation v = √(2gh), where v is the speed, g is the acceleration due to gravity (9.8 m/s²), and h is the height from which the ball was dropped.

2. Is the speed of the ball affected by the weight of the ball?

No, the speed of the ball dropped from a building is not affected by its weight. The speed is only dependent on the height from which it was dropped and the acceleration due to gravity.

3. How can kinetic energy be calculated from the speed of a ball dropped from a building?

The kinetic energy of a ball dropped from a building can be calculated using the equation KE = 1/2 * m * v², where KE is the kinetic energy, m is the mass of the ball, and v is the speed of the ball.

4. Does air resistance affect the speed and kinetic energy of a ball dropped from a building?

Yes, air resistance can affect the speed and kinetic energy of a ball dropped from a building. As the ball falls, it will encounter air resistance which will slow it down and decrease its kinetic energy. However, for small objects like a ball, the effect of air resistance is usually negligible.

5. How can the final velocity of a ball dropped from a building be calculated?

The final velocity of a ball dropped from a building can be calculated using the equation vf = √(vi² + 2ad), where vf is the final velocity, vi is the initial velocity (which is 0 in this case), a is the acceleration due to gravity, and d is the distance or height the ball has fallen.

Similar threads

Replies
1
Views
549
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
21
Views
1K
  • Introductory Physics Homework Help
Replies
6
Views
2K
  • Introductory Physics Homework Help
Replies
32
Views
2K
Replies
10
Views
411
  • Introductory Physics Homework Help
Replies
4
Views
810
  • Introductory Physics Homework Help
Replies
20
Views
950
  • Introductory Physics Homework Help
Replies
6
Views
1K
  • Introductory Physics Homework Help
Replies
6
Views
2K
Back
Top