# Acceleration and constant speed question

Can someone tell me which of the these is true or false and possibly explain it to me?

a)The acceleration of a car is zero when it is turning right at a constant speed
b)The acceleration of a car is zero when it is driving up a long straight incline at constant speed
c)The acceleration of a car is zero when it is topping the crest of a hill at constant speed
d)The acceleration of a car is zero when it is bottoming out at the lowest point of a valley at constant speed
e) The acceleration of a car is zero when it is speeding up as it descends a long straight decline.

Any help would be great.

thanks

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dextercioby
Homework Helper

Daniel.

DB
These are fairly easy questions if you just Think. Consider acceleration as the rate of change in speed, in your case ou can even think of it as a change in speed. Think of forces dependent on inclinations.

Make sure you know exactly what acceleration is. In order for an object to accelerate, its velocity must be changing.

dextercioby
Homework Helper
THE VELOCITY VECTOR MUST BE CHANGING WITH TIME AS TO HAVE A NONZERO ACCELERATION VECTOR...

Daniel.

Is this correct?
a) false because direction is changing
b) true
c) true
d) true
e) false because magnitude of the accerlation is changing

dextercioby
Homework Helper
The way i see it,only B is true...

Daniel.

dbzsongoku said:
Is this correct?
a) false because direction is changing
b) true
c) true
d) true
e) false because magnitude of the accerlation is changing
why does your argment for a not apply to c and d?

HallsofIvy