Physics help? In outer space a rock with mass 4 kg, and velocity m/s, struck a r
ID: 1462389 • Letter: P
Question
Physics help? In outer space a rock with mass 4 kg, and velocity m/s, struck a rock with mass 17 kg and velocity m/s. After the collision, the 4 kg rocks velocity is m /s. What is the final velocity of the 17 kg rock? What is the change in the internal energy of the rocks? Delta Eintenal = 1.402e7 x J Which of the following statements about Q (transfer of energy into the system because of a temperature difference between system and surroundings) are correct? (Ignore heat transfer by radiation.) Check all that apply: Q approx. 0 because there are no significant objects in the surroundings. Q = delta K of the rocks. Q = delta Einternal of the rocks. Q approx. 0 because the duration of the collision was very short.Explanation / Answer
Use the expression for kinetic energy: KE = 0.5 m v2
Find Initial Kinetic Energy before collision,
KE1 = ( 0.5 ) (4 ) (4000^2+ 3200^2+2800^2) + ( 0.5 ) (17 ) (240^2 + 310^2 +180^2)
= 69741850 J
Find final kinetic energy:
KE2 = ( 0.5 ) (4) (3500^2+ 2500^2+3100^2) + ( 0.5 ) (17 ) ( 357.65^2 +474.74 ^2 + 109.41^2 )
= 59324728.1747
Therefore, the change in internal energy = 69741850 J - 59324728.1747
= 10417121.8253 J
= 10417 kJ