a fan is rotating at 90 rpm.It is then switched off. It stops after 21 revolutions. calculate the time taken by the frictional t
1 answer:
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THE BALL'S ACCELERATION IS 130.90
Explanation:
According to Newton's second law "the force (F) acting on an object is equal to the mass (m) of an object times its acceleration (a)", meaning that when the soccer player kicks a ball, a force is acting on the ball, therefore increasing it's acceleration
SO FOR CALCULATING THIS WE WILL USE NEWTON LAW,
FORCE = MASS × ACCELERATION
WE ARE GIVEN
FORCE = 57.6N
MASS= .44KG
SO HERE WE APPLYING FORMULA ,WE WILL GET
ACCELERATION =
ACCELERATION =
ACCELERATION =130.90
Answer:
a) KE = 888.26J
b) N = 294.5 turns
Explanation:
For the kinetic energy:
The inertia is:
So, the kinetic energy will be:
Now, friction force is:
Ff = μ*N = 0.80*5N = 4N
The energy balance would be:
Kf - Ko = Wf where Kf=0; Ko = 888.26J; and Wf is the work done by friction force.
Wf = -Ff*d = -Ff*N*2*π*R where N is the amount of turns it gives.
Replacing these values into the energy balance:
0-888.26=-4*N*2*π*0.12
-888.26=-0.96*π*N
N=294.5 turns
The final combined velocity after the collision is 20.2 m/s
Explanation:
We can solve this problem by using the law of conservation of momentum: in fact, in absence of external forces, the total momentum of the two car and of the truck must be conserved before and after the collision.
This means that we can write the following equation:
where:
is the mass of the sport car
is the initial velocity of the car (taking its direction as positive direction)
is the mass of the truck
is the initial velocity of the truck
is the final combined velocity of the car and the truck, after the collision
Re-arranging the equation and substituting the values, we find the velocity after the collision:
And the positive sign indicates their final direction is the same as the initial direction of the two vehicles.
Learn more about momentum here:
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