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needhelp83
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1)If the coefficient of kinetic friction between a 35-kg crate and the floor is 0.3, what horizontal force is required to move the crate at a steady speed across the floor?
FN=mg=(35 kg)(9.8 m/s2)=343 N
Ffr= kF N=(0.30)(343 N)=102.9 N
2)A 1200-N crate rests on the floor. How much work is required to move it at constant speed
a) 4 m along the floor against a friction force of 230 N
b) 4 m vertically?
a)
W G = mgxcos90°=0
W N = FNxcos90°=0
W net = (Fnet)xx=( Fnet – Ffr)x= (1200 N – 230 N)(4 m)= 3880 J
b)
W G = mgxcos90°=0
W N = FNxcos90°=0
W net = (Fnet)x=( Fnet – Ffr)x= (1200 N – 0)(4 m)= 4800 J
Just wanting to make sure I am doing everything correctly.
FN=mg=(35 kg)(9.8 m/s2)=343 N
Ffr= kF N=(0.30)(343 N)=102.9 N
2)A 1200-N crate rests on the floor. How much work is required to move it at constant speed
a) 4 m along the floor against a friction force of 230 N
b) 4 m vertically?
a)
W G = mgxcos90°=0
W N = FNxcos90°=0
W net = (Fnet)xx=( Fnet – Ffr)x= (1200 N – 230 N)(4 m)= 3880 J
b)
W G = mgxcos90°=0
W N = FNxcos90°=0
W net = (Fnet)x=( Fnet – Ffr)x= (1200 N – 0)(4 m)= 4800 J
Just wanting to make sure I am doing everything correctly.