Question

RU' (J/ky"К) 2150 Aluminum 921 Acetone Brass 402 Benzene 1800 377 Bromine Ethyl alcohol 470 2400 840 126 Gasoline 2220 2095 461 Copper Glass Gold Ice Iron Lead Nickel Silver Styrofoam Zinc 130 502 Glycerin Kerosene Mercury Olive oil Petroleum Toluene Water 2430 2010 140 1970 2130 1720 4186 239 1131 390 Part 1: Bullet A 67 g bullet is fired from a height of 270 m. The initial speed of the bullet is 104 m/s. The bullet eventually comes to rest in a bucket containing 2.9 kg of gasoline that is at ground level. As a result of bringing the bullet to a stop (any change in PE while in the gasoline is negligible), how much does the temperature of the gasoline increase (express the answer in K)? Also determine how fast the bullet is going at impact. Ignore air drag and assume that all of the thermal energy generated goes into heating the gasoline. Impact speed = AT = Part 2: Nail A 0.78 kg hammer strikes a 17 g nickel nail into a wood board. The nail is horizontally aligned and at the moment of impact with the nail, the hammer had a speed of 9.7 m/s. Assume both the hammer and the nail come to a stop and that all of the thermal energy generated goes into heating the nail. Determine how much the temperature of the nail will increase after one hit and how many hits it will take to increase its temperature 95°C. AT after one hit = Minimum number of hits needed to increase the temperature by at least 95°C = hits

Answer 1

104m Isec mass of Ballet - 67gram Velouty of Bullet loumise height - 270m Impact speed . lo using Energy conservation. V t Kf Nitki -

fight 1 mo? - lug ² + o qed x 270+ (1042 - 1 vg2 => 2646 + 10 8 16 - IV - . vf = 26924 164.00ml sec AT - 2 0. There is no loss of Heat there ris kinetic energy increase the Terp or goes to thermal Enery e know that - Q - MSAT = 1 m. vf 99 .. AT = mort Oool 0.067 kg x 26924 0X 2 mg Sq 2x 2.9 x 2220 AT = 0.14 K

mus 0.78 kg Mn = 179 = 0.01719 intial speed of Hammen = 9.7m/sec - Vf - O for Both and nail All Energy goes into thernal Energy . - mSAT - LMxq X V.. - . AT= I my v² a my su x 0.70x19.7) 2 a 0.017 X 502 1.29K bno of hits Terp. to 95°c to increase the K=C+273-15 K= 360.15K - .: 4.29K Temp. IK Tenp Increase By : 1 hit U.29 360 15K » 1024 = 85. 6 66 Hits