Answer:
B. Magnetic Force
Explanation:
two pieces of irons cannot attract each other unless at least one of them is magnetize. That force is called magnetism.
So we want to know what is the purpose of a lanyard attached to a safety switch. So in case the operator falls overboard a safety switch is installed and connected to the operators hand or waist. Which ever is more practical. This safety switch turns off the motor.
Answer:
Explanation:
Given
mass of archer 
Average force 
extension in arrow 
Work done to stretch the bow with arrow


This work done is converted into kinetic Energy of arrow

where v= velocity of arrow



(b)if arrow is thrown vertically upward then this energy is converted to Potential energy




Answer:
3.57 m/s
Explanation:
The sum of the 2 momentums Is equal the finale momentums. so if momentums Is q, v Is velocity and m Is Mass, q3=m1*v1+m2**v2=16+9=25 m*kg/s
q3=m3*v3
v3=q3/m3=25/(4+3)=3.57m/s