Answer:
- <u>77.8 m/s, downward</u>
Explanation:
For uniform acceleration motion, the average speed is equal to half the soum of the initial velocity, Vi, and the final velocity, Vf
- Average speed = (Vf + Vi)/2
Also, by definition, the average speed is the distance divided by the time:
- Average speed = distance / time
Then:
Other kinematic equation for uniform acceleration is:
Since the window is falling and the air resistance is ignored, a = g (gravitational acceleration ≈ 9.8m/s²)
Replacing the known values we can set a system of two equations:
From (Vf + Vi)/2 = 300m/6.62s
(Vf + Vi) = 2 × 300m/6.62s
- Vf + Vi = 90.634 equation 1
From Vf = Vi + a×t
Vf - Vi = 9.8 (6.62)
- Vf - Vi = 64.876 equation 2
Adding the two equations:
- Vf = 77.8 m/s downward (velocities must be reported with their directions)
Your answer is 8. You add 2 + 1 + 5.3 to get 8.3. You round down to 8 because of the sig fig rules.
9*
m
Explanation:
Step 1:
We are given the initial length of the Pyrex glass dish at a particular temperature and need to calculate the change in the length when the temperature changes by 120° C. The coefficient of linear expansion of Pyrex is provided.
Step 2:
Change in length = Coefficient of linear expansion * Change in temperature * Initial length
Step 3:
Coefficient of linear expansion = 3*
/°C
Change in temperature = 120°C = 120 K
Initial length = 0.25 m
Step 4:
Change in length = 3* * 120 * 0.25 = 9* m
3. Law: Every action has a reaction equal in magnitude and opposite in direction.
hey guy
the vibration per second is frequency
then for 20 vibration time taken is 100 second
in 1 second 20/100 vibration took place
it means 0.2 is frequency
for time period , we have
t=1/f
=1/0.2
=5
