A stone is thrown, at an initial speed of 15 m/s from the top of a 20 m high cliff, while another stone is thrown vertically from the bottom of the cliff upwards also at a speed of 15 m/s. Determine:
a) After how long and at what height do the stones intersect?
b) Does the stone throw from below reach the top of the cliff?

A rocket is launched vertically from the ground at an initial speed of 200 m/s, after 10 seconds it explodes. A ground observer is located at a distance of 2000 meters in the same horizontal as the launch point. After how long he will hear the blast noise? The speed of sound in the air is 340 m/s.

On the Moon, a stone is released, at rest from a height of 20 meters. It falls, under the action of the lunar acceleration due to gravity, until reaching the ground with a speed v. Find how high the stone should be dropped on Earth, so that it hits the ground at the same speed v. The acceleration due to gravity on Earth g_E = 9.8 m/s², acceleration due to gravity on the Moon g_M = 1.6 m/s².

The velocity-time graph v = f(t) describes the motion of a body:

Find:
a) The displacement between 1 s and 9 s;
b) The average speed between 1 s and 9 s;
c) The average acceleration between 1 s and 9 s.

A particle starts a straight motion with an initial speed of 1 m/s. Given the acceleration-time graph from the start of the movement. Find:

a) The velocity at t=8 s;
b) The velocity at t=12 s;
c) The velocity at t=14 s;
d) Between, which time interval the speed decreases.

The equation of motion is


where position (S) is measured in meters and time (t) is measured in seconds:
a) Make a table with values for t from 0 to 8 s, and from the table plot the graph of the function;
b) When does the particle pass through the origin of the coordinate system?
c) When does the particle change its direction?