Velocity of a ball (kg) droped from height (m)

Click For Summary
To determine the greatest velocity of a 0.5 kg ball dropped from a height of 5 m, two approaches can be utilized: the energy approach and the kinematics approach. The energy approach states that the potential energy at the height converts entirely into kinetic energy just before impact. The kinematics approach involves using time-independent equations to calculate the final velocity. The gravitational acceleration is given as 9.8 m/s², which is essential for both methods. Additional guidance can be provided if needed, as the problem is straightforward.
Pippa9
Messages
1
Reaction score
0

Homework Statement



A ball of mass 0.5kg is dropped from a height of 5m what is the greatest velocity it will have just before hitting the ground?

Homework Equations



f=m*g
a= change in velocity/change in time


The Attempt at a Solution


m=.5kg
h=5m
a=9.8m/s

f=m*g
f= .5*9.8= 4.9N

I don't know what other equations to use to find velocity
 
Physics news on Phys.org
You can solve this one of two ways:

Energy approach: Energy at highest point is equal to the kinetic energy at the lowest point, since all potential energy is converted to kinetic as the ball is about to hit the ground.

Kinematics approach: Use the time independent kinematics equation.

Post if you need more specific guidance, because this is a relatively simple problem.
 
You can also use these equations together to solve:
d=0.5at2+v_{i}t+d_{i}
a=\frac{Δv}{Δt}.
 
Last edited:
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

Replies
10
Views
3K
Replies
7
Views
3K
  • · Replies 38 ·
2
Replies
38
Views
4K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
Replies
34
Views
2K
Replies
14
Views
3K
Replies
12
Views
1K
  • · Replies 13 ·
Replies
13
Views
1K
  • · Replies 17 ·
Replies
17
Views
2K