Question

An object is found to be moving toward the sun at a rate of 2.39 × 104 m/s. It will take 1.5 hours to reach the sun, and its average acceleration will be 12 m/s2. What will its final velocity be when it collides with the sun's surface?

Answer 1

The object is moving by uniform accelerated motion, so its velocity as a function of time is given by

`v(t)=v_0 + at`
where
`v_0 =2.39 \cdot 10^4 m/s` is the initial velocity of the object,
`a=12 m/s^2` is its acceleration and t is the time.

The object reaches the Sun after a time t=1.5 h, which corresponds to (keeping in mind that 1 h=3600 s)

`t=1.5 h=5400 s`
So, the velocity of the object when it reaches the Sun is

`v=v_0+at=2.39 \cdot 10^4 m/s + (12 m/s^2)(5400 s)=8.87\cdot 10^4 m/s`