What is the initial velocity of 20km/h, a car accelerated at 8m/s^2 for 10 seconds.
a. What is the position of the car at the end of the 10 seconds?
b. What is the velocity of the car at the end of the 10 seconds?
Answers
Answer:With an initial velocity of 20 km/h, a car accelerated at 8 m/s2 for 10 seconds.
a) What is the position of the car at the end of the 10 seconds?
b) What is the velocity of the car at the end of the 10 seconds?
Solution to Problem 2:
a) The car has an initial velocity of 20 km/h, therefore the initial speed u = 20 km/h. Nothing is said about the initial position and we therefore assume it is equal to 0. Hence the position x is given by the equation
x = (1/2) a t 2 + u t
where a is the acceleration (=8 m/s2) and t is period of time between initial and final positions and u is the initial velocity.
Since the time is given in seconds, we need to convert 20 km/h into m/s as follows:
u = 20 km/h =
20 * 1km
1 hour
1000 m
1 km
1 hour
3600 seconds
= 5.6 m/s
We now have
x = (1/2) (8) 102 + 5.6*10 = 456 m
b) v = at + u = 8*10 + 5.6 = 85.6 m/s
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