Work
The unit for work
In a race, two cars have the
same mass but different
velocities. The car with the
slower velocity has
kinetic energy than the other
car does.
Less
Electric Blanket
Electrical 🡪 thermal
The amount of work done
in a certain time is…
Power
Energy in motion is known as...
Kinetic Energy
You move a cart of pumpkins 15
m. This requires a force of 65 N.
How much work was done while
moving the pumpkin?
975J
How much energy does a 4
kg apple have that is thrown
at a speed of 2 m/s?
8J
Windmill
Kinetic 🡪 electrical
How much power is used if a
100 J of work is done to move
a box in 10 s?
10 W or 10 J/s
A 0.9 kg pineapple falls from a tree
that is 5.8 m tall. How much
energy does the pineapple have?
51.16J
The two conditions that must be met in order for work to be done.
1. The object must move
2. Force must be applied in the direction of the motion
List the type of potential
energy each object below
has.
Sandwich
Trampoline
Chemical potential energy
Elastic potential energy
Fireworks
Chemical 🡪
radiant/thermal/sound
How long would it take to
do 36 J of work if 4 W of
power are available?
9s
How much heat is needed
to warm 0.098 kg of gold
from 15°C to 30°C if gold
has a specific heat of 136
J/kg°C?
200J
A small child weighs 25 N.
If they do a somersault and
move a distance of 3 m,
how much work was done?
75J
How much potential energy
does a bird have that
weighs 9 N and is sitting
on a branch 3 m high?
27J
An apple falling off a tree
limb
GPE 🡪 kinetic
How much power is used if
a force of 70 N is used to
push a box a distance of
20 m in 5 s?
280W
Define thermal energy and
mechanical energy.
Thermal energy = the sum of
kinetic and potential energy of
particles in an object
Mechanical energy = the sum
of kinetic and potential energy
in a system
How far did you push a 12
kg barrel of tools if you did
276 J of work and pushed
at a rate of 3 m/s2?
7.67m
What is the mass of a picture
that falls off a shelf 6 m high
and has 150 J of energy?
2.55kg
A man eating dinner, then
tap dancing
Chemical 🡪 kinetic 🡪
sound/thermal
A motorcycle and its rider have a
mass of 28 kg. If the cart
accelerates at 6 m/s2 during a 40
m sprint in 100 s, how much
power did the cart have?
67.2W
What is the mass of a ball
that is rolling with a speed
of 26 m/s and has 1,200 J
of energy?
3.55kg