A car has a constant acceleration of 5 m/s/s. At some time it is traveling at 40 m/s. How fast will it be going, one second later?
a.) 30 m/s
b.) 40 m/s
c.) 45 m/s
d.) 200 m/s
well velocity increases by 5m/s every second, right?
Understanding what acceleration means gives you the immediate answer without any calculation.
If at any one time, the velocity is 40 m/s and that velocity changes 5 m/s every second, then one second later it must be 45 m/s
a*t = 40.
5t = 40, t = 8 s.
V = a*t = 5(8+1) = 45 m/s.
To find the answer, we need to use the kinematic equation that relates velocity, acceleration, and time:
v = u + at
Where:
v is the final velocity
u is the initial velocity
a is the acceleration
t is the time
Given that the car has a constant acceleration of 5 m/s/s, we know the value of a is 5 m/s/s. The initial velocity u is 40 m/s, and we want to find the final velocity v after 1 second of time.
Plugging the values into the equation, we have:
v = 40 m/s + (5 m/s/s) * 1 s
v = 40 m/s + 5 m/s
v = 45 m/s
Therefore, the car will be traveling at a speed of 45 m/s, which corresponds to option c.) in the answer choices.