Forces, Magnetisjm, and Electrogmagnetism Flashcards
If a physical quantity has both magnitude and direction, is it a vector or a scalor.
Vector for example.e momentum
-Describe an investigation to find the link between force applied and the extension of a spring
. Measure the springs initial length. with a ruler clamped to a stand.
Add a mass to the spring and record the new length of the spring. Calculate the extension as the
change in length (take away the natural length). Continue to add masses and calculate the
extension.
Give the typical speed of a person walking, running and cycling.
Walking 1.5 m/s
Running 3 m/s
Cycling 6 m/s
- Give the quantities that can be calculate from the gradients of:
a. Distance – Time graphs
b. Velocity – Time graphs
a. Speed
b. Acceleration
Name the two forces acting on a skydiver that determine their terminal velocity.
Weight and drag (caused by air resistance). If the two forces are equal then a sky diver has
reached terminal velocity.
- Define each of Newton’s three laws.
First: If the resultant force acting on an object is zero and:
The object is stationary, the object remains stationary
The object is moving, it will continue to move at the same speed and in the same direction. So
velocity stays the same.
Second: The acceleration of an object is proportional to the resultant force acting on the object,
and inversely proportional to it’s mass. Force = mass x acceleration.
Third: Whenever two objects interact, the forces they exert on each other are equal and opposite.
Give the resultant force acting on an object which moves with constant velocity (same speed
and direction).
The resultant force is zero according to Newton’s first law.
Name and describe the two components of stopping distance.
Stopping distance = thinking distance + braking distance.
Thinking distance is how far the car travels during the driver’s reaction time.
Stopping distance is how far the car travels once the brakes are applied
- Explain what affects:
a. The thinking distance of a vehicle
b. The braking distance of the vehicle
a. This is reaction time so tiredness, drugs, speed and distractions.
b. Adverse road conditions (wet or icy), poor brakes, poor tyre condition, speed
Explain the difference between elastic and inelastic deformation of a spring.
An elastic object returns to its original shape and length after a force is removed, the extension is
directly proportional to force applied.
Inelastic objects do not return to their original shape or length and the extension is not directly
proportional to force applied.
Describe the shape of the line on a velocity-time graph for an object travelling at steady speed.
A straight, horizontal line
Describe how the design of a car can
help to minimise air resistance. Describe why parachutes work in the opposite way.
Car design : stream, linedshape to reduce sir resistance
Parachutes: large surface area to maximuse sir resistance and slow descent
Describe the term inertia.
Inertia is the tendency of an object to continue in their state of rest or of uniform motion. It is used
to describe Newton’s first law of motion.
Describe the energy transfer that occurs when a car brakes. Explain what affect this has on
the brakes.
Energy is transferred from the kinetic energy stores of the wheels to the thermal energy stores of
the brakes. This causes the brakes to heat up.
Give two methods which can be used to measure someone’s reaction time. Recall typical
reaction times.
Use computer-based test (e.g. Clicking the mouse when the screen changes colour). Another is
the ruler drop test where, without giving any warnings, a ruler is dropped from zero between a
person’s thumb and forefinger and they catch the ruler as quickly as possible. Both tests need to
be repeated as it is hard to do the tests accurately.
Describe a wavelength.
The distance from a point on one wave to the equivalent point on the adjacent wave
- Define frequency and give the units.
The number of waves passing a point each second, measured in Hertz (Hz).
- Name the type of wave that has vibrations that are perpendicular (at 90°) to the direction of
energy transfer.
Transverse wave
Name the waves of the electromagnetic spectrum in order.
Radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, gamma rays.
- Name the wave in the electromagnetic spectrum that has the highest frequency.
Gamma rays
Name the wave in the electromagnetic spectrum that has the longest wavelength.
Radio waves
Name the wave in the electromagnetic spectrum that can have hazardous effects on human
tissue.
Ultraviolet, X-rays and gamma rays. Ultraviolet, X-rays and gamma rays.
Name the wave in the electromagnetic spectrum that can have hazardous effects on human
tissue.
Ultraviolet, X-rays and gamma rays.
Name the wave in the electromagnetic spectrum that can cause mutations of genes and cancer.
X-rays and gamma rays.
