Answer:
85.5 km/h
Explanation:
= time interval for first phase = 14 min = 
h = 0.233 h
= time interval for second phase = 46 min = 
h = 0.767 h
= average speed for the entire trip = 74 km/h
= average speed in first phase = 36 km/h
= average speed in second phase
= distance traveled in first phase
= distance traveled in first phase
average speed is given as
km/h
Melting
we know that ice melts at 0 ⁰C. in the graph, at position B, the temperature is constant, which indicates that phase change is taking place there. at B , from the graph , we also notice that the temperature is constant at value 0 ⁰C. this indicates that ice at 0 ⁰C is converting to water at 0 ⁰C there at position B in the graph.
hence the correct choice is Melting.
Combustion Engine Exhaust----Cars, trucks, jet airplanes and other combustion engine vehicles cause air pollution. The exhaust from these contains carbon monoxide, nitrous oxide and gaseous oxide. This type of air pollution creates smog
Answer:
Explanation:
The acceleration of an object is the rate of change of velocity of the object.
Mathematically, it is calculated as:
where
u is the initial velocity
v is the final velocity
t is the time taken for the velocity to change from u to v
Acceleration is a vector, so it is important to also take into account the direction of the velocity.
For the particle in this problem, we have:
u = +48 m/s is the initial velocity (positive direction)
v = -92 m/s is the final velocity (negative direction)
t = 4.5 s is the time interval
Therefore, the average acceleration is
