help with kilometers

Question

1.  a car starts a journey of 100 kilometers with a beginning speed of 25 kilometers per hour.  It completes the journey in 2 hours.  what was the "average" speed of the car.

 

a. 25 km/h       b.  50 km/h        c.  100 km/h

 

2.  a car drives around a circle at a steady 25 kilometers per hour.  this car

 

a.  has a constant speed

b.  has a constant velocity

c.  both a and b

d.  none of these

 

 

3.  Is the car in #2

 

a.  accelerating

b.  is acted up by a net force greater than 0

c.  both a and b

d.  none of these

Answer 1

1. average speed =dist/time =100/2 =50 km/h so the answer is b.

 

 

2.You are given that the care is driven at 25 km/h which is a constant speed so the answer is a.

 

 

3.You are given that he car is traveling in a circle so it's velocity (direction) is changing so it is accelerating and is acted on by centripetal force. So the answer is c.

 

Jim