In which situation is the acceleration of the car negative?
A)
The velocity of a car was 75 km/h over 4 hours.
B)
The velocity of a car reduced from 50 km/h to 35 km/h over one minute.
C)
The velocity of a car increased from 40 km/h to 75 km/h over 15 minutes.
D)
The velocity of a car was 45 km/h at 2:00 pm and at 4:00 pm the velocity of the car was 85 km/h.

Question

In which situation is the acceleration of the car negative?
A)
The velocity of a car was 75 km/h over 4 hours.	
B)
The velocity of a car reduced from 50 km/h to 35 km/h over one minute.	
C)
The velocity of a car increased from 40 km/h to 75 km/h over 15 minutes.	
D)
The velocity of a car was 45 km/h at 2:00 pm and at 4:00 pm the velocity of the car was 85 km/h.

anonymous · Answer

@Brrandyn  Help please!! Im begging you!

brrandyn · Answer

Acceleration is defined as the rate of velocity over a time interval: 
$$a =\frac{ Δv }{ t}$$

Therefore, the difference in the final velocity must be less than the initial velocity.

$$a = \frac{ Vf - Vi }{ t }$$

The answer is:
B) 35 - 50 = negative acceleration.

anonymous · Answer

Thank you so much!!!!!! ;D

brrandyn · Answer

Sure! :) Sorry for the slow typing.

anonymous · Answer

Its fine! :)