Kinematics rock thrown up in air

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SUMMARY

The discussion focuses on the kinematics of a rock thrown upward on Mars with an initial velocity of 22 m/s, described by the height equation H = 22t - 1.86t². The velocity of the rock at time t is calculated as V = 22 - 3.72t. The rock reaches the surface at t = 11.83 seconds, and the final velocity upon impact can be determined using the equation V = Vinitial - a*t. The gravitational acceleration on Mars is 1.86 m/s², which is crucial for these calculations.

PREREQUISITES
  • Understanding of kinematic equations, specifically H = ut + 0.5at²
  • Familiarity with gravitational acceleration on Mars (1.86 m/s²)
  • Knowledge of velocity calculations using V = u + at
  • Basic algebra for solving quadratic equations
NEXT STEPS
  • Calculate the final velocity of the rock using V = Vinitial - a*t at t = 11.83 seconds
  • Explore the effects of varying initial velocities on projectile motion
  • Study the differences in gravitational acceleration between Earth and Mars
  • Learn about the implications of conservative fields in physics
USEFUL FOR

Students studying physics, particularly those focusing on kinematics and projectile motion, as well as educators seeking to enhance their teaching methods in these topics.

ankit arya
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kinematics ... rock thrown up in air

Homework Statement




If a rock is thrown upward on the planet Mars with a velocity of 22 m/s, its height (in meters) after t seconds is given by H = 22t - 1.86t^2.
Find the velocity of the rock when t = a.
When will the rock hit the surface?
With what velocity will the rock hit the surface?

Homework Equations


v=u+at



The Attempt at a Solution


i found the ans for first two ques but i am not able to solve the third one.

velocity at t=a is 22-3.72a
rock will hit the surface at t=11.83s

pls help me with the third one...
 
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Welcome to PF.

Gravity is a conservative field. So at the same height going up ...

|Vinitial| = |Vfinal|

... going down.

Or you could do it the long way and evaluate

V = Vinitial - a*t

Using the total time of flight.
 


thanks i got that!
 

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