- #1
Vinhster
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Homework Statement
Hello everyone, i have been stuck on this question on the Physics year 12 Nelsons textbook, and it is pissing me off because I've been working so hard on it and i can not get it.
It is in the chapter of Movement in one and two dimensions.
The question is:
A person pushes a lawnmower of mass 20 kg at a constant speed with a force of 100 N directed along the handle, which is at 35 degrees to the horizontal.
What force must the person exert on the lawnmower in order to give it a velocity of 2.0 m/s in 2.5 s?
Most appreciated for the help everyone thank you.
Homework Equations
I think it's relevant to Tcos(theta) = ma > 0
The Attempt at a Solution
I drew a diagram and labeled all the units.
Where:
t = 2.5
v = 2
u = 0
So i used the formula : v = u + at
where i concluded with 2 = 0 + a2.5
a = 2/2.5
a = 0.8 m/s^2
and then i subbed it into the equation
F = ma
where i concluded with F = (20)(0.8)
= 16 N
But the answer in the back of the book says it's 120N =/