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13physicsdude
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HELP! Is my answer correct?? Is negative Friction possible?!?
A dogsled team has four dogs that pull a person and a sled with a combined mass of 100 kg.
A) They start from rest and reach a speed of 45 km/h in 2.5s. What is the average force applied by each dog?
B) Suppose each dog can pull with a force of magnitude 150 N. What is the frictional force acting on the sled
A)
a=Vf-Vi/t
a=45-0/2.5
a=45/2.5
a=18 m/s2
Fnet=ma
Fnet=(100)(18)
Fnet=1800N/4 dogs
Fnet=450 N
∴ Average force applied by each dog is 450 NB)
T-Ff=ma
600-Ff=ma
600-Ff=100(18)
600-Ff=1800
Ff=600-1800
Ff=-1200 N
∴ the Frictional force acting on the sled is -1200 N
Is my answer correct for part A and B ?? Its for an assignment due tomorrow and I want to make sure its correct.
Homework Statement
A dogsled team has four dogs that pull a person and a sled with a combined mass of 100 kg.
A) They start from rest and reach a speed of 45 km/h in 2.5s. What is the average force applied by each dog?
B) Suppose each dog can pull with a force of magnitude 150 N. What is the frictional force acting on the sled
The Attempt at a Solution
A)
a=Vf-Vi/t
a=45-0/2.5
a=45/2.5
a=18 m/s2
Fnet=ma
Fnet=(100)(18)
Fnet=1800N/4 dogs
Fnet=450 N
∴ Average force applied by each dog is 450 NB)
T-Ff=ma
600-Ff=ma
600-Ff=100(18)
600-Ff=1800
Ff=600-1800
Ff=-1200 N
∴ the Frictional force acting on the sled is -1200 N
Is my answer correct for part A and B ?? Its for an assignment due tomorrow and I want to make sure its correct.