Motion and forces Flashcards
What is a scalar?
It a magnitude (size) but no specific direction
What is is a vector?
It has both magnitude (size) and specific direction
What does velocity mean?
Speed in a stated direction
What is the equation for speed, distance and time
Speed=distance/time
How do you work out the distance traveled?
Distance travelled =average speed x time
How do you calculate acceleration?
a=(v-u)/t
What are the the range of laboratory methods for determining speeds of objects as the use of light gates?
using a high speed pulsed laser, a beam splitter, mirrors and fast detectors and oscilloscope
What is the typical speed for wind?
about 12 m/s
What is the typical speeds for sound?
331.29 m/s
What is the typical speed for walking?
Between 1.2 and 1.4 m/s
What is the typical speed for running?
Between 4 and 6 mph
What is the typical speed for cycling?
15.9 mph
What is the typical speed for car?
13-30 m/s
What is the typical speed for a train?
56 m/s
What is the typical speed for plane?
250 m/s
What is acceleration in free fall?
10 m/s*2
What is Newton’s first law
an object remains in the same state of motion unless a resultant force acts on it
What is Newton’s second law?
a force to be equal to change in momentum (mass times velocity) per change in time.
What is the calculation needed for Newton’s second law?
F = m x a
What is the calculation needed for weight?
W =m x g
How is weight measured?
a measure ofthe force of gravity on a physical object and is measured in newtons.
What is the relationship between the weight of a body and the weight of the gravitational field strength?
directly proportional
What is Newton’s third law?
whenever two objects interact, they exert equal and opposite forces on each other.
What is the equation for momentum?
p = m x v
What is human reaction times and recall typical results?
0.2 seconds
What is stopping distance of a vehicle is made up of the sum of the thinking distance and the braking distance?
Stopping distance = Thinking distances +breaking distance
Give three examples of things that can effect the stopping distance?
The mass of the car
The speed of the vehicle
The driver’s reaction time
What are the effects of a driver’s reaction time when they are drunk or have used drugs?
ability to judge speed and distance. reaction and coordination skills. blurry or impaired vision.
