# How Much Force is Needed to Jump?

• localrob
In summary, the person must push off the ground with a force of 25.04 m/s2 in order to jump 2.0 m into the air.

#### localrob

If I wanted to know how much force is required to jump, and I know my acceleration while jumping, would I just use F=ma. Or do I need to account for gravity, as in use
Fjump - Fg = ma

if the acc. you find is the net acc. then i guess you don't need to consider gravity as ots already considered while finding the net acc.

Yeah, that's what I was thinking.
Initially I was given the final velocity when jumping and the time in contact with the ground.
Vf = vi + at
That should be my net acceleration, because that is the actual acceleration needed to reach Vf.

If the question is what force do I need to push off the ground with, then aren't I looking for Fnormal and not net force?
The force that I push off the ground with is equal/opposite to the force normal acting on me.
So shouldn't I be solving FN - Fg = ma for FN?

please can you provide full question

Question:
If someone is able to jump 2.0 m into the air
a) How what speed must they leave the ground with?(ignore air resistance)
b) If they are in contact with the ground for 0.25 sec and have a mass of 65kg, what force must they push off the ground with?

Solution:
a) Going from the ground to max height
vi = ?, vf = 0m/s, a = -9.8m/s2, $$\Delta$$y = 2.0m
vf2 = vi2+2ay
vi = 6.26m/s

b) just for the jumping part
vi = 0m/s, vf = 6.26m/s, a = ?, t = 0.25
Find acceleration using vf=vi +at
a = 25.04 m;s2

Now, as you read the question, do you think it's asking for the net force applied to the person to jump or is it asking what the person must push off with?

net force acting on man must be now ma
this will include the gravity force and the normal reaction acting on him

localrob said:
Now, as you read the question, do you think it's asking for the net force applied to the person to jump or is it asking what the person must push off with?

I guess they are asking the force with which the man must push the ground, which is the normal rxn acting on it

cupid.callin said:
I guess they are asking the force with which the man must push the ground, which is the normal rxn acting on it

Yes I agree with you. I think they are asking for the normal force.
Thanks for the help.

## 1. What is the force required to jump?

The force required to jump varies depending on factors such as the individual's weight, leg strength, and technique. On average, it takes about 4-6 times a person's body weight in force to jump.

## 2. How does the force required to jump differ for different sports?

The force required to jump can vary significantly between different sports due to the specific movements and techniques involved. For example, basketball players typically need to generate more force to jump compared to long jumpers.

## 3. What muscles are involved in generating the force required to jump?

The main muscles involved in generating the force required to jump are the quadriceps, glutes, and calf muscles. These muscles work together to extend the legs and propel the body upwards.

## 4. Can the force required to jump be increased?

Yes, the force required to jump can be increased through regular strength and plyometric training. By strengthening the muscles involved in jumping and improving explosive power, an individual can increase the force they can generate while jumping.

## 5. How does gravity affect the force required to jump?

Gravity plays a significant role in the force required to jump. The higher the gravitational pull, the more force is needed to overcome it and jump. This is why individuals can jump higher on the moon, where gravity is weaker compared to Earth.