A guy pushes off the ground with a force 50% greater than his weight. What is his upward acceleration?

Question

mathsadness · Answer

please help

amistre64 · Answer

force = mass*acceleration

mathsadness · Answer

i know....

anonymous · Answer

Well if his force is 50% more than his mass.. We have force = 1.5(mass)

mathsadness · Answer

weight does not equal mass.....

anonymous · Answer

Fair enough.

amistre64 · Answer

weight is a result of mass

anonymous · Answer

If you prefer then, wieght = mg = 9.8(mass)

mathsadness · Answer

what is the answer

anonymous · Answer

42

mathsadness · Answer

fail

mathsadness · Answer

9.8 * 1.5

mathsadness · Answer

enough jokes

mathsadness · Answer

right???

anonymous · Answer

force = 1.5(weight)
weight = 9.8(mass)
force = (mass)(acelleration)
Therefore
(1.5)(9.8)(mass) = (mass)(acelleration)
Therefore acceleration is 1.5 * 9.8 (assuming the mass is in kilos)

mathsadness · Answer

no cuz then he would accelerate upwards and not decellerate back to the ground

mathsadness · Answer

it must be negative

anonymous · Answer

Is this a math problem or a physics problem?

mathsadness · Answer

and it is weight - 1.5 weight= -0.5 weight= -4.9

mathsadness · Answer

obviously a physics problem, but it involves math

mathsadness · Answer

i think the answer is -4.9

mathsadness · Answer

m

anonymous · Answer

If it's a physics problem then you have to do the sum of the forces.

$$F_{up} - F_{g} = ma$$$$\implies 1.5(F_g) - F_g = ma$$$$\implies .5(F_g) = ma$$$$\implies .5(mg) = ma$$$$\implies a = .5g$$
Where g is either 9.8 or 32 depending on whether the mass is in kilos or in slugs.

mathsadness · Answer

but the acelleration must be negative!!!!!

mathsadness · Answer

silly!!!

anonymous · Answer

no. If it was negative he'd never get off the ground. And he'd be travelling into the dirt.

mathsadness · Answer

nope! negative means he reaches a peak in his jump and doesnt keep going faster into space. duh.

anonymous · Answer

If you are so confidant.. answer it yourself. I am correct. He only has a negative acceleration once he's stopped pushing and his feet have left the ground. And in that scenario his acceleration will always be -mg.

mathsadness · Answer

it depends on what part of the jump you are talking about

anonymous · Answer

once his feet have left the ground it doesn't matter how hard he was pushing. His acceleration will always be -g because gravity is the only force acting on him.

anonymous · Answer

so I must assume it's talking about his acceleration before he leaves the ground otherwise his force wouldn't make any difference.