An object is dropped from rest.
What is its instantaneous speed when it has
been in motion for 7 s? The acceleration of
gravity is 9.8 m/s
2
.
Answer in units of m/s
Consider only vertical component (because the object does not move horizontally)
Use formula v=u+at
v=0+9.8(7)
v=68.6m/s
To find the instantaneous speed of an object that has been in motion for 7 s, we can use the equation:
v = gt
where v is the instantaneous speed, g is the acceleration due to gravity, and t is the time.
Given that the acceleration due to gravity is 9.8 m/s^2 and the object has been in motion for 7 s, we can substitute these values into the equation:
v = (9.8 m/s^2)(7 s)
Multiplying the numbers together, we get:
v = 68.6 m/s^2
Therefore, the instantaneous speed of the object when it has been in motion for 7 s is 68.6 m/s.
To find the instantaneous speed of an object that has been in motion for 7 seconds, we need to use the formula for the velocity of an object in free fall:
v = gt
where:
v is the velocity or speed of the object,
g is the acceleration due to gravity (9.8 m/s^2),
and t is the time the object has been in motion.
In this case, the object is dropped from rest, so its initial velocity (u) is zero. Therefore, we can use the formula for velocity:
v = u + gt
Since u is zero, the formula simplifies to:
v = gt
Now we can substitute the values into the formula:
v = 9.8 m/s^2 * 7 s
v = 68.6 m/s
Therefore, the instantaneous speed of the object after being in motion for 7 seconds is 68.6 m/s.