Physics, asked by gharjai930, 1 year ago

A child of mass 40 kg jumps off a wall and hits the ground at 4 m/s. He bends his knees and stops in 1s. Calculate the force required to slow him down. How would this force be different if he didn't bend his knees and stopped in 0.1s ?

Answers

Answered by Anonymous
4

KE = Ft

Solve for F

his acceleration is 4m/s^2

F = ma

1/10 the time means 10 times the acceleration.

Answered by techkaleab1
4

Answer:

1600N

Explanation:

force applied at 1s: 160N

force would increase to 1600N at 0.1s

Explanation:

F=mΔvt

force = mass * change in velocity / time

at 1s:

mass: 40kg

change in velocity (taking downwards as a positive direction):

4 m/s to rest =4−0=4 m/s

time: 1 s

mΔvt=1601=160

force applied =160N

at 0.1s:

mΔvt=1600.1=1600

force applied = 1600N

note that in the equation for force applied, time is the denominator.

this means that force is inversely proportional to time - as force increases, time decreases, and vice versa.

if the time is divided by a certain amount, the new force can be found by multiplying the previous force by that same amount.

here, dividing the time by 10, from 1s to 0.1s, multiplies the force by 10, from 160N to 1600N.

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