Answer:
Both balls hit the ground simultaneously
Explanation:
Let´s call b₁ ( the ball dropped ) the equation for a free fall movement is, tacking as the origin of coordinates the level from which it was dropped
V = g*t ( since V₀ initial velocity is 0 )
In the case of projectile movement the equation for Vx and Vy (these speeds are independent)
are:
Vx = V₀x (constant) and Vy = Voy + g*t
Vy = V₀ * sin 0⁰ + g*t Vy = 0 + g*t
As we can see V is the same in both cases then the balls hit the ground simultaneously
Answer:
a) about 20.4 meters high
b) about 4.08 seconds
Explanation:
Part a)
To find the maximum height the ball reaches under the action of gravity (g = 9.8 m/s^2) use the equation that connects change in velocity over time with acceleration.
In our case, the initial velocity of the ball as it leaves the hands of the person is Vi = 20 m/s, while thw final velocity of the ball as it reaches its maximum height is zero (0) m/s. Therefore we can solve for the time it takes the ball to reach the top:
Now we use this time in the expression for the distance covered (final position Xf minus initial position Xi) under acceleration:
Part b) Now we use the expression for distance covered under acceleration to find the time it takes for the ball to leave the person's hand and come back to it (notice that Xf-Xi in this case will be zero - same final and initial position)
To solve for "t" in this quadratic equation, we can factor it out as shown:
Therefore there are two possible solutions when each of the two factors equals zero:
1) t= 0 (which is not representative of our case) , and
2) the expression in parenthesis is zero:
Turning on a light switch converts mechanical energy to electrical and radiant energy. So Mechanical energy
<span>62 x 9.8 x 12= 7 291.2! Hope this is helpful!</span>
ANSWER
B - Air density is lower, so there is less heat transfer
EXPLANATION
We want to identify why temperature decreases with higher altitude.
When radiation is absorbed by the earth's surface, it heats the surroundings and the air through convection and conduction.
However, as we ascend higher into the atmosphere, the amount of solar radiation absorbed by the troposphere's gases decreases significantly.
Due to less heat transfer, air molecules start to move away from each other causing a decrease in air density
Hence, we see that temperature decreases with increasing altitude because there is less heat transfer due to the lower air density.
The answer is option B.