Physic's EXAM- True/False
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- An object in a circle at a constant speed is accelerating.
- True
- Slope on a displavement versus time graph is speed.
- False
- If a position-time graph is concave up, then there is + acceleration.
- True
- Slope on a velocity time graph is acceleration
- True
- Area on a velocity time graph is speed
- False
- Inertia is the force that makes the planets orbit the sun.
- False
- Landing a ship on Saturn would be easy because it has a solid surface
- False
- The sun is closer to the earth in summer making it warmer
- False
- The tail of a comet is always behind the comet
- False
- The oort cloud is a nebula
- False
- Fusion is the splitting of atoms
- False
- Iron is the most stable atomic nucleus
- True
- The core of a red giant is hotter than its surface
- True
- The mass of a star determines where it is plaved on the Main Sequence
- False
- The hotter an object is, the redder it appears.
- False
- Small stars like our sun fuse carbon into iron
- False
- Microwaves are more energetic than visible light
- false
- White dwarf stars fuse helium in their cores
- True
- Very large stars have more mass so they live longer than smaller stars
- False
- A B2 type star that appears very dim is very far away.
- true
- The principle of inertia accounts for the horizontal motion of a projectile.
- True
- The net force acting on a projectile is zero
- False
- The verticle potition-time graph of a projectile is concave up
- false
- the slope of the horizontal position time graph of a projectile is zero
- true
- the acceleration at the top of a projectile's trajectory is zero
- false
- temperature is a measure of heat
- false
- heat is energy transferred mechanically
- false
- a force is an agent of change measured in joules
- false
- a force is conservaive if the work moving around a closed path is zero
- true
- there is pure energy that can be isolated from a system
- true
- the units kg*m/s^2 are equivalent to a joule
- false
- the units for the sine or cosine of an angle are degrees
- false
- positive work produces an increase in enegery
- true
- positive potential energy is associated with attractive forces
- true
- if the total energy of a sustem is zero, then it is a bound system
- true
- momentum is a measure of the intensity of motion
- true
- momentum is conserved in all collisions
- true
- kinetic energy is conserved in all collisions
- false
- if momentum is conserved, then the venter of mass movies constantly
- true
- a closed system for momentum is also closed for kinetic energy
- false
- the units kg*m/s^2 are equivilent to a newton-second
- false
- the product of force and distance is impulse
- false
- an impulse causes a change in momentum
- true
- if a system is accelerating then its momentum is conserved
- false
- when two masses collide, they must make contact
- false
- Model rockets may be constructed out of metal
- false
- the momentum of the rocket is conserved during its flight
- false
- the chemical energy in the fuel is converted into kinetic energy
- true
- during its flight, a model rocket becomes more stable
- true
- a rocket motor pushes against the ground to lift the rocket
- false
- a solar sail uses collisions with photons for thrust
- true
- CA glue is a good choice for gluing plastic parts
- false
- epoxy is a chemical mix of a resin and a hardener that is exothermis
- true
- epoxy is more difficult to use but provides a very high strength bond
- true
- a model rocket is less than 1500 g and uses a G motor or less
- true