Answer:
7.09683 m
1.20285 s
2.4057 s
11.8 m/s
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration
g = Acceleration due to gravity = 9.81 m/s² (negative up, positive down)
From equation of motion we have

The maximum height above the ground that the ball reaches is 7.09683 m

Time taken to go up is 1.20285 s it will take the same time to come down so total time taken to reach the ground after it is shot is 1.20285+1.20285 = 2.4057 s

The velocity just before it hits the ground is 11.8 m/s
Answer:
Yes
Explanation:
The plank (also called a front hold, hover, or abdominal bridge) is an isometric core strength exercise that involves maintaining a position similar to a push-up for the maximum possible time
The work-energy theorem says that the total work done on the block is equal to the difference of its kinetic energies at points B and A. Then the total work done on the block is

Friction acts on the block to oppose its motion, so it does negative work on the block, -4.5 J.
The only other force acting on the block as it moves is the force <em>P</em>. Let
be the work done by the force <em>P</em>. Then the total work done on the block is

Answer:
W = 112.58 N-unit
Explanation:
Given:
- Force F = 10 N
- Angle Q of force with x axis: 30 degrees
- distance to be moved d = 13 units along + x axis
Find:
Work Done by the force F:
Solution:
The work by force in positive x direction can only be done if the both the direction of distance traveled and direction of force are parallel vectors. Hence we compute the component of Force F in x direction F_x:
F_x = F*cos(Q)
F_x = 10*cos(30)
F_x = 8.66 N
Hence,
Work Done by force
W = F_x * d
W = 8.66 * 13
W = 112.58 N-unit
I think that the answer is C)