Calculating Speed for High Jump of 1.60m

  • Thread starter Thread starter 5t34lth
  • Start date Start date
  • Tags Tags
    Jump Speed
AI Thread Summary
To calculate the speed required for a 70-kg high jumper to reach a height of 1.60 m, the relationship between kinetic energy and gravitational potential energy is used. The equations involved are Kinetic Energy = 0.5(mass)(velocity^2) and Gravitational Potential Energy = (mass)(acceleration due to gravity)(height). By setting the change in potential energy equal to the change in kinetic energy, the equation simplifies to -1097.6 + 35vi^2 = 0. Solving this results in a required takeoff speed of 5.6 m/s. This analysis demonstrates the energy conservation principle in the context of high jumping.
5t34lth
Messages
3
Reaction score
0

Homework Statement


At what speed would a 70-kg high jumper have to leave the ground in order to raise his body up to a height of 1.60 m

Acceleration due to gravity: 9.8 m/s^2 [down]

Homework Equations



Kinetic Energy = 0.5(mass)(velocity^2)
Gravitational Potential Energy = (mass)(accleration due to gravity)(height)

The Attempt at a Solution

 
Physics news on Phys.org
Answer is 5.6 m/s but i don't know how to get it
 
Because only conservative forces are acting upon the system:
Change in Potential Energy + Change in Kinetic Energy = 0
Change in potential energy = mg(hf-hi)
Change in kinetic energy = .5(m)(vf2-vI2)
vf is zero because the jumper just reaches the maximum height of 1.6 meters. hi is also zero because the jumper starts on the ground. hf is 1.6 meters. Substituting, we obtain
-1097.6 + 35vi2 = 0 (Because gravity points down, it has a value of -9.8 m/s20
Solving for v results in the answer of 5.6 m/s.
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'

Thread 'Calculation of Tensile Forces in Piston-Type Water-Lifting Devices at Elevated Locations'

Figure 1 Overall Structure Diagram Figure 2: Top view of the piston when it is cylindrical A circular opening is created at a height of 5 meters above the water surface. Inside this opening is a sleeve-type piston with a cross-sectional area of 1 square meter. The piston is pulled to the right at a constant speed. The pulling force is（Figure 2）： F = ρshg = 1000 × 1 × 5 × 10 = 50,000 N. Figure 3: Modifying the structure to incorporate a fixed internal piston When I modify the piston...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Calculating the Force of a Jump on the Moon
Replies
10
Views
3K
Understanding the Bungee Jumper Problem: Energy Transformation and Calculations
Replies
44
Views
6K
How High Can a Dog Jump by Exerting Maximum Force?
Replies
7
Views
3K
How High Can You Jump on asteroid 243 Ida?
Replies
5
Views
4K
How high will UT bounce on a bungee jump from the Golden Gate Bridge?
Replies
6
Views
2K
Work Pulley Problem with constant speed
Replies
2
Views
985
Calculating Force - Basketball player landing from a jump
Replies
2
Views
3K
Max KE of a squirrel jumping from the top of a tree
Replies
6
Views
2K
Calculating Kangaroo Jump Distance: How High Can They Go?
Replies
14
Views
3K
Elliptical orbit/ determine speed & potential energy
Replies
1
Views
1K

Hot Threads

Recent Insights

Back
Top