Answer:
height from where rock was thrown is 27.916 m
Explanation:
speed = 7.50 m/s
θ = 30°
g= 9.8 m/s²
horizontal distance = 18 m
time require for vertical displacement
t = 2.8 sec
now for calculation of height
s = ut + 0.5 a t²
-h = v sinθ× t + 0.5 ×(-9.8)× (2.8²)
-h = 7.5 sin30°× 2.8 - 0.5 ×(9.8)× (2.8²)
-h = -27.916 m
h= 27.916 m
height from where rock was thrown is 27.916 m
Answer:
0.147 J
Explanation:
The total energy that has been transformed into thermal energy is equal to the loss of gravitational potential energy between the initial situation (bob at h=0.5 m above the ground) and the final situation (bob back but at h=0.45 m above the ground).
Therefore, we have
where
m = 0.3 kg is the mass of the bob
g = 9.8 m/s^2
h1 = 0.5 m is the initial height
h2 = 0.45 m is the final height
Substituting, we find the thermal energy
Therefore, the energy transformed into thermal energy is 0.147 J.
The hang time of the student is 0.64 seconds, and he must leave the ground with a speed of 3.13 m/s
Why?
To solve the problem, we must consider the vertical height reached by the student as max height.
We can use the following equations to solve the problem:
<u>Initial speed calculations:</u>
At max height, the speed tends to zero.
So, calculating, we have:
<u></u>
<u>Hang time calculations:</u>
We must remember that the total hang time is equal to the time going up plus the time going down, and both of them are equal,so, calculating the time going down, we have have:
Then, for the total hang time, we have:
Have a nice day!