Inclined throw - motorcycle jumps from the ramp

[Karol]

Inclined throw -- motorcycle jumps from the ramp

Homework Statement

The motorcycle jumps from the ramp. what is the minimum speed at the edge in order to reach the other side.

Homework Equations

Constant acceleration: V=-gt

The Attempt at a Solution

The time to reach height of 1.5 meters:
$$V_0\sin30^0=gt \rightarrow t=\frac{V_0}{2g}$$
The horizontal distance:
$$V_0\cos30^0\cdot \frac{V_0}{2g}=10$$
$$V_0=15.2 [m/sec]=54.7 [km/h]$$
And it should be about 45 [km/h]

 

[mfb]

The time to reach height of 1.5 meters:
$$V_0\sin30^0=gt \rightarrow t=\frac{V_0}{2g}$$

Only if the motorcycle does not have a vertical velocity at the upper point. This is not true here. It will follow a parabolic path and "fall down" a bit at the end, this increases the time.

You'll have to consider both horizontal and vertical motion together.

 

[paisiello2]

First equation is wrong one.