A motorist travels due North at 90 km/h for 2 hours. She changes direction and travels West at 60 km/for 1 hour. a) Calculate the average speed of the motorist [4]
b) Calculate the average velocity of the motorist.

a. 50km/hr.

b. 10km/hr

Explanation:

Average speed, which is calculated by dividing the total distance travelled by the time interval as follows:

Average speed = total distance travelled ÷ time

Average velocity is calculated by dividing the total displacement by the time interval as follows:

Average velocity = change in displacement (∆x) ÷ time (t)

According to this question, a motorist travels due North at 90 km/h for 2 hours. She then changes direction and travels West at 60 km/for 1 hour.

Total distance of this journey is 90 + 60 = 150

Total time taken = 1 + 2 = 3hours

Average speed = 150/3

= 50km/hr.

b.) Average velocity = x2 - x1/t

Average velocity = 90 - 60/3

= 30/3

= 10km/hr

gpe = mass x gravity constant x height or… gpe = mgh

where… mass: measured in kilograms (kg)

gravity: gravity constant on earth = 10.00 m/s2

height: measured in meters (m)

gpe: measured in joules (j) or kilojoules (kj)

how do you solve gpe?

gravitational potential energy (gpe) is the energy an object has because of its position above the. ground.

gpe = mass x gravity constant x height or… gpe = mgh.

mass:

note: to earn full marks when solving science word problems, you must show your work:

formula.

example:

given values:

mass = 0.3 kg.