If a car travelling at 60.0 km/h [S] stops in a time of 3.50 s, its acceleration is:
Question 10 options:
A)
4.77 m/s² [S]
B)
4.77 m/s² [N]
C)
16.7 m/s² [S]
D)
16.7 m/s² [N]
E)
17.1 m/s² [S]
C) 16.7 m/s² [S]
To find acceleration, we can use the equation:
acceleration = (final velocity - initial velocity)/time
Since the car stops, the final velocity is 0. The initial velocity can be found by converting 60.0 km/h to m/s:
initial velocity = 60.0 km/h * 1000 m/km * 1 h/3600 s = 16.7 m/s [S]
Now we can plug in the values:
acceleration = (0 - 16.7 m/s)/3.50 s = -4.77 m/s² [S]
The negative sign indicates that the acceleration is in the opposite direction to the initial velocity (i.e. deceleration). However, the question asks for the magnitude of the acceleration, so we take the absolute value and get:
|acceleration| = |-4.77| m/s² = 4.77 m/s² [S]
Therefore, the answer is option C.