Answer:
a) 69.3 m/s
b) 18.84 s
Explanation:
Let the initial velocity = u
The vertical and horizontal components of the velocity is given by uᵧ and uₓ respectively
uᵧ = u sin 40° = 0.6428 u
uₓ = u cos 40° = 0.766 u
We're given that the horizontal distance travelled by the projectile rock (Range) = 1 km = 1000 m
The range of a projectile motion is given as
R = uₓt
where t = total time of flight
1000 = 0.766 ut
ut = 1305.5
The vertical distance travelled by the projectile rocks,
y = uᵧ t - (1/2)gt²
y = - 900 m (900 m below the crater's level)
-900 = 0.6428 ut - 4.9t²
Recall, ut = 1305.5
-900 = 0.6428(1305.5) - 4.9 t²
4.9t² = 839.1754 + 900
4.9t² = 1739.1754
t = 18.84 s
Recall again, ut = 1305.5
u = 1305.5/18.84 = 69.3 m/s
Given:
Height of tank = 8 ft
and we need to pump fuel weighing 52 lb/ 
to a height of 13 ft above the tank top
Solution:
Total height = 8+13 =21 ft
pumping dist = 21 - y
Area of cross-section = 
= 
=16
Now,
Work done required = 
= 
= 832
![[ 21y ]_{0}^{8} - [\frac{y^{2}}{2}]_{0}^{8}\\](https://tex.z-dn.net/?f=%5B%2021y%20%5D_%7B0%7D%5E%7B8%7D%20-%20%5B%5Cfrac%7By%5E%7B2%7D%7D%7B2%7D%5D_%7B0%7D%5E%7B8%7D%5C%5C)
)
= 113152 = 355477 ft-lb
Therefore work required to pump the fuel is 355477 ft-lb
It would need to be over 20 because if the load of the Pulley E is 20 and the effort is 20, then they will be equal and the Pulley would not move, so your answer is at least 20
Answer:
B transferred.
Explanation:
The kinetic energy is simply transferred by transforming it into other forms of energy.
According to the law of conservation of energy "energy is neither created nor destroyed but transformed from one form to another".
- The moving baseball posses kinetic energy
- As it hits the bat, it is converted to mechanical and thermal energy.
- The bat warms up due to the transfer of the kinetic energy.
- The mechanical energy of the bat cause work to be done on it and it breaks apart.
- This ensures that the energy in this process is conserved.
