Answer:
The answer would be 735J
Explanation:
PE=mgh
=(mass)(force of gravity)(height)
=(25kg)(9.8m/s^2)(3m)
=735J
Answer:
A. The shorter the distance the greater the force, so now the force would have increased because they haven't moved away from each other.
B. The force would decrease because they are now further apart.
C. the force wouldn't be as great as before but the force would still be high because they are not far apart from each other.
I hope this helps you( ◜‿◝ )♡
Answer:
True
Explanation:
When a ray travelling parallel to the principle axis of a concave mirror then the light ray reflect out through the mirrors and passing through the focus.
When a light ray travelling through focus of a concave mirror then after reflection the light ray reflect out through the mirror and go parallel to principle axis.
Therefore, rays travelling parallel to the principle axis of a concave mirror will reflect out through the mirrors focus.
It is true.
Answer:
22.5 m
Explanation:
Using v² = u² - 2gy where u = initial velocity of BB = 21 m/s, v = final velocity of BB = 1 m/s (since this is the required speed of BB in which it will not harm the birds), g = acceleration due to gravity = 9.8 m/s² and y = minimum height of BB above the gun at which the birds may safely fly.
Substituting the values of the variables into the equation, we have
v² = u² - 2gy
(1 m/s)² = (21 m/s)² - 2(9.8 m/s²)y
collecting like terms, we have
(1 m/s)² - (21 m/s)² = - 2(9.8 m/s²)y
1 m²/s² - 441 m²/s² = -(19.6 m/s²)y
simplifying, we have
- 440 m²/s² = -(19.6 m/s²)y
dividing through by -19.6 m/s², we have
y = - 440 m²/s² ÷ -19.6 m/s²
y = 22.45 m
y ≅ 22.5 m
