Physics 1 Flashcards
What is the equation for distance?
distance = speed x time
What is the equation for time?
time = distance/speed
What is the equation for speed?
speed = distance/time
A sprinter runs 100 m in 10 sec. What is their speed? (don’t forget the units!!)
10 m/s
Calculate the speed of a car that takes 90 sec to travel 360 m (don’t forget the unit!!)
4 m/s
Calculate the speed of a train that travels 2.7 km in 1.5 mins. Give your answer in m/s
30 m/s
How long does it take for a boat travelling at 8 miles/hour to travel 10 miles? Give the unit
75 mins
What are forces?
Forces are pushes or pulls that can change the motion of an object
What are examples of forces?
weight
friction
air resistance
upthrust
What are forces measured in?
Newtons
What are the forces for a stationary duck sitting on a lake?
Upthrust (upwards)
Weight (downwards)
What is mass?
Amount of matter (stuff)
Measured in kg
Same everywhere
What is weight?
A force due to GRAVITY
Measured in Newtons
Changes on different planets
What is the equation for calculating weight?
Weight (N) = Mass (kg) x Gravitational field strength (N/kg)
w = m x g
Describe gravitational field strength
This is different for different planets
Units are N/kg
Earth: g = 10 N/kg
Moon: g = 1.6 N/kg
Calculate the weight of a man on earth who has a mass of 73 kg
730 N (73 kg x 10 N/kg = 730 N)
Calculate the weight of a tiger on earth who has a mass of 196 kg
1960 N (196 kg x 10 N/kg = 1960 N)
Calculate the weight of a screwdriver on earth having a mass of 0.44 kg
- 4 N
0. 44 kg x 10 N/kg = 4.4 N
Weight is the _______ of gravity due to the pull of the Earth or other objects. It is measured in _______ because it is a force
force
Newtons
force
The mass of an object is how much ______ there is. Your mass does not depend on where you are and is measured in _____
matter
kg
Newton said that all objects in the universe experience gravity. The size of the gravitational force depends on the ______ of the objects and the _______ between them
mass
distance
If an object is taken to the Moon it weighs only about one _____ as much as it does on Earth, because the Moon is ______ than the Earth. On Jupiter the object would weigh ______, because Jupiter is ______ than Earth
sixth
lighter
more
heavier
To change mass into weight on Earth you ____ by ___. To change weight on Earth into mass you ____ by ___.
times
10
divide
10
To change mass into weight on the Moon you ____ by ____. To change weight on the Moon into mass you ____ by _____.
times
1.6
divide
1.6
To use the weight and mass equation, the mass must be in _____
kg
The weight and mass equation is:
w = m x g
Gravity is a ______ force
pulling
Your mass always _________ on different planets
stays the same
You weight ______ on different planets
varies
What is Hooke’s Law?
When an elastic object - such as a spring - is stretched, the increased length is called its extension.
The extension of an elastic object is directly proportional to the force applied to it
This means if we double the force we double the extension
What is meant by deforming an object?
It means changing an object’s shape
What is meant by an elastic object?
What is an example of an elastic object?
Elastic objects change shape when a force is exerted on them
A spring, rubber band
What is the formula for Hooke’s Law?
F = k x e F = force measured in Newtons k = the 'spring constant' measured in Newtons per metre (N/m) e = extension measured in metres
A spring has a spring constant of 60 N/m. Calculate the force needed to extend it by 0.1 m
6 N
The extension of an elastic object is _______ ________ to the force applied to it
directly proportional
Hooke’s law is a ________ relationship
linear
Hooke’s law only applies ______ a certain force
up to
For example, if a spring is stretched too much, it will not return to its original length when the load is removed
