In april 1974, steve prefontaine completed a 10 km race in a time of 27 min, 43.6 s. suppose "pre" was at the 8.13 km mark at a time of 25.0 min. if he accelerated for 60 s and then maintained his increased speed for the remainder of the race. calculate his acceleration over the 60 s interval. assume his instantaneous speed at the 8.13 km mark was the same as his overall average speed up to that time.

Explanation:

Given

Total time=27 min 43.6 s=1663.6 s

total distance=10 km

Initial distance

time taken=25 min =1500 s

initial speed

after 8.13 km mark steve started to accelerate

speed after 60 s

distance traveled in 60 sec

time taken in last part of journey

distance traveled in this time

and total distance

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.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.