أسئلة فيزياء .. أتمنى تشاركوني في حلها

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1- Using a wrench 0.4 m long, a force of at least 100 N is needed to turn a nut.
a. How large a torque is required?
b. How large a force is needed to turn the nut using a wrench 0.15 m long?



2- On a horizontal air track, a spring exerts an average force of 2N on a cart of mass 0.4 kg.
a. Find the acceleration of the cart.
b. If the car accelerates from rest to 0.3 m/s. for how long a time is the force applied?




3- A ball thrown straight upward has a height x above the ground which is given by the equation x = (19.6 m/s)t – (4.9 m/s2)t2. find the average velocity from
a. t = 0 to t = 2 s
b. t = 2 to t = 4 s.





4- A car initially moving at 20 m/s brakes with an acceleration of 2 m/s2. how long will it take for the car to stop?


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