12 Physics 2.1 Quiz

One assumption made when using equations to predict the motion of a projectile is:

• that there is zero air resistance

• the hight of a launched projectile is not important

• the value for gravity varies with height

• that horizontal nd vertical components of velocity are independent

Another assumption made when using equations to predict the motion of a projectile is:

• that the maximum velocity of an object is at the very top of a projectile's motion

• That there is zero velocity at the top of a projectile's motion

• That there is a constant value for gravity of 9.8 m/s/s

• That gravity does not exist in space

The path of a projectile described by the projectile motion equations has the shape of a:

• exponential

• hyperbolic graph

• semi-circle

• parabola

Newton's second law describes the force due to gravity on a falling object. This law can be described as:

• F=ma

• for every action there is an equal and opposite reaction

• the law of inertia

• acceleration = change in velocity/time

The ............................ of an object does not affect the rate at which it falls.

A ball is allowed to free fall from a height of 50m. Ignoring air resistance and using 9.8 m/s/s as the value for g, calculate the time the ball takes to hit the ground.

• 2.5 seconds

• 2.8 seconds

• 3.2 seconds

• 3.5 seconds

A ball is allowed to free fall from a height of 50m. Ignoring air resistance and using 9.8 m/s/s as the value for g, calculate the velocity of the ball at the point of impact.

• 24.6 m/s

• 27.3 m/s

• 29.1 m/s

• 31.3 m/s

Another assumption for projectile motion questions is that the horizontal velocity of the object can be considered to be ................