Projectile Problem - Time of Peak (1 Viewer)

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

If a fireworks rocket has an initial upward speed of 58 m/s when launched, for how long will it coast before reaching its peak?

So could I use the equation t=v0z/g?

When I use this I get the peak to be 5.9s. Is v0z = 58 m/s or would that be 0? Am I approaching this correctly?
Anyone have an idea?
well you need an angle because time would depend on the angle you use. For example if you launched the rocket at a 50 degree angle the time to reach its peak would be 58sin50 / 9.81 = 4.42 secs. But if you launched the rocket at a 70 degree angle it would be 58sin70 / 9.81 = 5.55 seconds. So you would have to specify the angle.
oh ok, so even if you shoot the firework straight up, it still needs an angle?
well straight up it would be 90 degrees. 58sin 90 / 9.81 = 5.912 seconds.


Staff Emeritus
Science Advisor

The Physics Forums Way

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving