Which a vector quantity: speed or velocity?

Initially, a particle is moving at 5.33 m/s at an angle of 37.9° above the horizontal. two seconds later, its velocity is 6.11 m/s at an angle of 54.2° below the horizontal. what was the particle's average acceleration during these 2.00 seconds in the x-direction (enter first) and the y-direction?

What is meant by the statement" the melting poin of glycerine is 13 degree celsius

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?