A projectile is fired out of a cannon at 50 km/s, at an angle of 30 degrees and an elevation of 10m from the ground. How long does it take for the projectile to hit the ground?

Find the verticle velocity by resolving the velocity vector:

Trigonometry: 50sin30 = 25m/s in upwards direction

Using SUVAT for the vertical direction: S=-10, U=25, A=-9.81, V=N/A, T=?:

s=ut+0.5at2 
In the upwards direction: -10=25(t)+0.5(-9.81)(t2

0 = -4.905(t2) + 25(t) +10

Solve quadratic using x = (-b+/-SQRT(b2-4ac))/2a

t = 5.47 seconds as negative solution cannot exist

LC

Related Physics A Level answers

All answers ▸

A car is moving along a straight horizontal road, with a constant acceleration. The car passes point A, with a speed of ums(-1). 10 seconds later, passes point B, with a speed of 45 ms(-1). The distance from A to B is 300m. Find u.


A piece of card is released from rest at a height of 0.5m above a light gate. It falls freely and a computer measures the velocity as it passes through the light gate to be 3.10m/s. What is the acceleration due to gravity measured by this experiment?


An ideal gas undergoes a transformation in which both its pressure and volume double. How many times does the root mean square speed of the gas molecules increase?


Explain how fluorescent tubes work