# AstroA4.docx - 1 In the figure below two balls collide Ball...

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1. In the figure below, two balls collide. Ball A with mass m1 = 30 kg is initially moving at 20 m/s. Ball B with mass m2 = 9 kg is moving at 10 m/s. After the collision, ball A is moving at 10 m/s. How fast is ball B moving? Assume that we have an elastic collision between the two balls. Momentum is conserved so the
2. Why is a torque wrench necessary to tighten bolts correctly on an engine head cover that sits on a gasket between it and the engine block? What might happen if a regular wrench is used to tighten the bolts? The torque wrench allows one to precisely set what attribute? (Note: A regular wrench and a torque wrench can both apply torque to a bolt.) [15 pts] _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ _______________________________________________________________________________________________________ Show your work here: [5 pts] Velocity of ball B after the collision is ______________________ m/s. [Round to 1 decimal.] [15 pts]
v2 = ? m/sv 1 = 10 m/su 1 = 20 m/s u2 = 10 m/s (30 20) + (9 10) = (30 10) + (9 ?) (m v)+ (m v) = (m v)+ (m v)m1 = 30 kgm 1 = 30 kg m2 = 9 kg m1 = 30 kg m2 = 9 kg m2 = 9 kgA B A BAfter collisionCollidesBefore collisionActivity #4 2 3. When you toss (underhand) or throw (overhand) a ball into the air, it will follow what kind of path or trajectory? (Hint: It is one of the conic sections.) [10 pts] _______________________________________________________________________________________________________ 4. The table shows the relative strength of gravity on major solar system bodies. If a person weighs 80 kg on Earth, how much will that person weigh on (a) Moon, (b) Venus, (c) Mars, and (d) Jupiter? (Assume that all of the bodies have a solid surface on which one can stand.) [30 pts total]
[Round all answers to 1 decimal.] [Each answer is worth 5 pts] (a) Weight on Moon = ______________ kg (d) Weight on Jupiter = ______________ kg (b) Weight on Venus = ______________ kg (e) Weight on Pluto = ______________ kg (c) Weight on Mars = ______________ kg 5. If orbital velocity around the Earth is 17,500 mi/h, how fast is this in (a) km/h? (b) km/s? (c) mi/s? [25 pts total]
[Round to all answers to 1 decimal.] [Each answer is worth 5 pts] (a) 17,500 mi/h = __________________ km/h (c) 17,500 mi/h = __________________ mi/s (b) 17,500 mi/h = __________________ km/s
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