If a car can go from 0 to 60 mi/hr in 8.0 seconds, what would be its final speed after 5.0 seconds if its starting speed were 50 mi/hr?
Answer (3)
v 1 ā = 60 h mi ā t 1 ā = 8.0 s = 3600 8 ā h = 450 1 ā h ā ā ā ā ā ā ā ā ā ā ā ā ā ā a = t v ā a = 450 1 ā 60 ā h 2 mi ā = 27000 h 2 mi ā ā ā ā ā ā ā ā ā ā ā ā ā ā ā v o ā = 50 h mi ā t = 5.0 s = 3600 5 ā h = 720 1 ā h ā ā ā ā ā ā ā ā ā ā ā ā ā ā
v = v o ā + a t v = 50 h mi ā + 27000 h 2 mi ā ā
720 1 ā h = 50 h mi ā + 37.5 h mi ā = 87.5 h mi ā ā A n s w er
a = t V ā ā a = 8 [ s ] 60 [ mi / h r ] ā t h e f ina l s p ee d a f t er 5.0 seco n d s V = 50 [ mi / h r ] + 5 [ s ] ā 8 [ s ] 60 [ mi / h r ] ā = 50 [ mi / h r ] + 8 5 ā ā 60 [ mi / h r ] = = 50 [ mi / h r ] + 37.5 [ mi / h r ] = 87.5 [ mi / h r ]
The final speed of the car after 5 seconds, starting from 50 mi/hr, is approximately 62.4 mi/hr. This was calculated using the initial speed, the acceleration from the initial condition, and the time duration. The acceleration was found to be 0.002083 mi/sĀ² from the speed change from 0 to 60 mi/hr over 8 seconds.
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