1.A 25.0 kg object is attracted towards the earth by a force of gravity of 75.0 N. How far from the earths centre is it?(adsbygoogle = window.adsbygoogle || []).push({});

my answer: g=Fg/m g=75N/25kg g=3 N/kg

2. A 250 kg freezer is being pushed across the floor at a constant speed by a force of 750N. What is the coefficient of friction between freezer and floor?

my answer: Fg=mg Fg=250kg(9.8N) Fg=2450kg/N

m=Fapplied/Fg m=750N/2450kg/N m=0.31kg

3. A piece cut from a bicycle inner tube is 0.70m long when it carries a load of 25.0 N the spring constant is 300 N/m. What will the length of the piece of rubber when the load is 75.0N?

my answer: F=Kx F=300N/m / 75.0N F=4m in length

4. A 60.0kg sled is coasting with a constant speed of 10.0m/s over smooth ice. It enters a 6m stretch of rough ice where the force of friction is 120N. With what speed does the sled emerge from the rough ice?

my answer: m=Ffr/Fn m=120N/588N m=0.2kg

a=????

5. A force of 5.0N gives a mass m1 and acceleration of 8.0m/s^2 and the same force gives mass m2 an acceleration of 24.0m/s^2. What acceleration would it give the two when they are fastened together?

my answer: a=Fnet/m a=5.0N/0.833kg a=6.0m/s^2

m1=(5.0N) / (8.0m/s^2) m1=0.625kg m2=(5.0N) / (24.0m/s^2) m2=0.208k

plz tell me if i messed up anywhere

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