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Title: Estimating force? Post by: jingle_morgan on Aug 21, 2014 Estimate the force on a 145-gram baseball if it hits the bat at 50 miles per hour and stays in contact with the bat for 0.1 second, during which time it reverses direction and leaves the bat at 75 miles per hour. Express the result in newtons and in pounds.
I;m not sure how i'm suppose to go about this problem. Anything would really help, Thanks lol Title: Re: Estimating force? Post by: duddy on Aug 21, 2014 Metric
====== 60 miles / hour = 60 * [1 hour / 3600 sec] * [1.6 km/1 mile]*[1000 m / 1 km] 60 miles / hour = 26.67 m/s By similar methods 75 mph = 33.33 m/s 145 grams = 145 / 1000 = 0.145 kg Why 1000 F = m*(v1 - v2)/ t I'll let you figure out why v2 is minus. Think about which way the ball is going. F = 0.145 kg (26.67 - (- 33.33) ) / 0.1 second F = 87 N English ====== m = 0.145 kg * 2.2 = 0.319 pounds (mass) 60 mph = 88 feet per second. 75 mph = 75 * 5280 / 3600 = 110 feet / second F = 0.319 * (88 - - 110)/0.1 F = 631 |