# Physics 101

posted by
**reda**
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What is the net force of a 5.0 N force and an 7.0 N force acting on an object for each of the following conditions?

(a) The forces act in opposite directions. ( )N

(b) The forces act in the same direction.( )N

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A force of 2.4 N is exerted on a 6.2 g rifle bullet. What is the bullet's acceleration?

( ) m/s2

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What is the force in newtons acting on a 4.6 kg package of nails that falls off a roof and is on its way to the ground?

( )N

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A small car with a mass of 800 kg travels northward at 28 m/s.

Does the car have more or less momentum than a truck with a mass of 12000 kg traveling eastward at 15 m/s?

more

less

How much more or less?

times

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Two ice skaters stand together as illustrated in Figure (a) below. They "push off" and travel directly away from each other, the boy with a velocity of v = 0.33 m/s to the left. If the boy weighs 728 N and the girl weighs 465 N, what is the girl's velocity after they push off? (Consider the ice to be frictionless. Enter the magnitude only.)

m/s

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An asteroid in an elliptical orbit about the sun travels at 1.5 106 m/s at perihelion (the point of closest approach) at a distance of 3.3 108 km from the sun. How fast is it traveling at aphelion (the most distant point), which is 9.2 108 km from the sun?

m/s

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