Tuesday, 23 September 2014

Projectiles Problems



In all these questions ignore air resistance unless otherwise stated.

Question 1
At t=0, a ball is thrown with an initial velocity of magnitude 15ms-1 at 75° to the horizontal (upwards).
a)Calculate the magnitudes of the vertical and horizontal components of its initial velocity.
b)Calculate the magnitude of the vertical component of velocity of the ball at t=0·5s.
c)Calculate the magnitude of the vertical component of velocity of the ball at t=2·0s. Which way is the ball moving at this time?
d)What is the magnitude of the horizontal component of velocity at t=2·0s?
Question 2
A projectile is thrown upwards at 60° to the horizontal with an initial speed of 30ms-1, calculate
a)the time taken for the projectile to return to its starting height
b)the range of the projectile (the horizontal distance moved over a horizontal surface).
Question 3

A ball is thrown upwards at 50° to the horizontal with an initial speed of 15ms-1. Calculate the magnitude of its velocity when it is at its maximum height.
Question 4

A ball is thrown with a velocity of 25ms-1 horizontally. Find the magnitude and direction of its velocity after 1·25s (assuming that the ball has not reached the ground at this time).
Question 5

An arrow is shot horizontally at a target 20m away. The arrow hits a point 19·6cm vertically below the point it was aimed at. Calculate the speed with which the arrow left the bow.