**F=ma FORCE = MASS x ACCELERATION**

**.**

**Remember, mass is in kg - - force in in N (newtons) - - acceleration is in m/s**

^{2}**1.**

**How much force is needed to accelerate a 66 kg skier at 2 m/sec**

^{2}?**2.**

**What is the force on a 1000 kg elevator that is falling freely at 9.8 m/sec**

^{2}?**3.**

**What is the acceleration of a 50 kg object pushed with a force of 500 newtons?**

**4.**

**The mass of a large car is 1000 kg. How much force would be required to accelerate the car at a rate of 3 m/sec**

^{2}?**5.**

**A 50 kg skater pushed by a friend accelerates 5 m/sec**

^{2}. How much force did the friend apply?**6.**

**A force of 250 N is applied to an object that accelerates at a rate of 5 m/sec**

^{2}. What is the mass of the object?**7.**

**A bowling ball rolled with a force of 15 N accelerates at a rate of 3 m/sec**

^{2}; a second ball rolled with the same force accelerates 4 m/sec^{2}. What are the masses of the two balls?**8.**

**If a 60 kg person on a 15 kg sled is pushed with a force of 300 N, what will be person’s**

**acceleration?**

**9.**

**A force of 20 N acts upon a 5 kg block. Calculate the acceleration of the object.**

**10.**

**An object of mass 300 kg is observed to accelerate at the rate of 4 m/s**

^{2}. Calculate the force required to produce this acceleration.**11.**

**A 5 kg block is pulled across a table by a horizontal force of 40 N with a frictional force of 8 N opposing the motion. Calculate the acceleration of the object.**

**12.**

**An object of mass 30 kg is in free fall in a vacuum where there is no air resistance. Determine the acceleration of the object.**

**13.**

**An object of mass 30 kg is falling in air and experiences a force due to air resistance of 50 newtons.**

**a.**

**Determine the net force acting on the object and**

**b.**

**calculate the acceleration of the object.**

**SOLUTIONS**

**1.f=ma f= 66 x 2 f = 132 N**

**2.**

**F= ma f= 1000 x 9.8 f=9,800 n****3.**

**F= ma 500 = 50(a) a= 10 m/s**^{2}**4.**

**F= ma f= 1000 x 3 f= 3000 N****5.**

**F = ma f= 50 x 5 f= 250 N****6.**

**F = ma 250N=(m)5 m= 50kg****7.**

**F= ma 15N= (m)3 m=5kg 15N = (m)4 m=3.75kg****8.**

**F=ma 300N=(60+15)(a) a=4 m/s**^{2}**9.**

**F=ma 20N=5(a) a=4 m/s**^{2}**10.**

**F=ma F=300 x 4 f= 1200N****11.**

**F=ma 40N-8N=32N of force in a direction 32N=5(a) a=6.4 m/s**^{2}**12.**

**Since it is in free fall and is falling due to the force of gravity.....the acceleration will**

**always be 9.8 m/s**^{2}**13.**

**f=ma f=30 x 9.8 f=294N Net force is 294-50 = 244N****acceleration of the object.**

**F= ma 244N=30 (a) a=8.13 m/s**

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