Answer:

Explanation:
This is a projectile motion problem. We will first separate the motion into x- and y-components, apply the equations of kinematics separately, then we will combine them to find the initial velocity.
The initial velocity is in the x-direction, and there is no acceleration in the x-direction.
On the other hand, there no initial velocity in the y-component, so the arrow is basically in free-fall.
Applying the equations of kinematics in the x-direction gives

For the y-direction gives

Combining both equation yields the y_component of the final velocity

Since we know the angle between the x- and y-components of the final velocity, which is 180° - 2.8° = 177.2°, we can calculate the initial velocity.

Answer with Explanation:
We are given that
A.Mass,m=12 kg


Speed,v=1.5m/s
Net force in x direction must be zero



Net force in y direction








Power,P=Fv

Where 
B.Substitute the values


Answer:
The velocity of the particle from T = 0 s to T = 4 s is;
0.5 m/s
Explanation:
The given parameters from the graph are;
The initial displacement (covered) at time, t₁ = 0 s is x₁ = 1 m
The displacement covered at time, t₂ = 4 s is x₂ = 3 m
The graph of distance to time, from time t = 0 to time t = 4 is a straight line graph, with the velocity given by the rate of change of the displacement to the time which is dx/dt which is also the slope of the graph given as follows;


The velocity of the particle from t = 0 s to t = 4 s = 1/2 m/s = 0.5 m/s.