QCE Unit 3 Physics Revision

Which is the correct formula for resolving initial velocity into it's vertical component

• $u\cos\theta$

• $u\sin\theta$

• $mg\cos\theta$

• $mg\sin\theta$

Which is the correct formula for the acceleration down an inclined plane?

• $g\sin\theta$

• $g\cos\theta$

• $mg\sin\theta$

• $mg\cos\theta$

Complete the sentence:

The horizontal and vertical components of a velocity vector are:

• independent of each other

• dependent on each other

• equal in magnitude but opposite in direction

The definition of the normal force is

• the force that an inclined plane exerts on an object placed on the plane

• the force equal to the weight force but opposite in direction

• the force acting along an imaginary line drawn perpendicular to the surface

• $F_N=mg\cos\theta$

An object is placed on an inclined plane that makes an angle of 30 degrees with the horizontal. It has a mass of 2kg. A force is applied up the plane of 80 N. Calculate the magnitude of the net force on the object and it's direction.

• 70.2N, down the plane

• 63.0N, down the plane

• 70.2N, up the plane

• 63.0N, up the plane

Uniform circular motion is when

• an object is swung on a string around a person

• an object that is moving in a circular path experiences acceleration in an outwards direction

• an object that is moving in a circular path experiences a force parallel to it's velocity

• an object that is moving in a circular path experiences a force perpendicular to it's velocity

Define average speed

• the rate of change of distance calculated by the formula:

  
  

  average speed = distance/time
  

• the first derivative of velocity

• the average of all the different velocities that an object experiences during it's motion

• the sum of all speeds divided by the number of speeds

The definition of period in circular motion is:

• the number of cycles completed every time interval

• the number of cycles completed every second

• the time taken to complete a single cycle

• time taken to complete one revolution

The best definition of centripetal acceleration is

• the acceleration experienced by any object moving in a circular path directed away from the centre of motion

• the acceleration experienced by any object moving in a circular path directed towards the centre of motion

• the acceleration experienced by any object moving in a circular path directed parallel to the motion

• the acceleration experienced by any object moving in a circular path directed perpendicular to the motion

the best definition of centripetal force is

• the force acting on an object travelling in a circle that constantly either pulls or pushes the object in towards the centre of motion

• the force acting on an object travelling in a circle that constantly pulls the object in towards the centre of motion

• the force acting on an object travelling in a circle that constantly pushes the object in towards the centre of motion