Answer:
Right hand thumb rule : It is a rule used to find the magnetic field direction around current carrying wire .
Explanation:
It states that : "If you grasp conductor in your right hand such that thumb points in upward direction ,then the direction in which our finger curls gives the direction of magnetic field or magnetic lines of forces" .
This rule proves that :Current can give rise to magnetism .
Around every current carrying conductor there exist a magnetic field which can be easily felt .
According to this rule : When a current flows in upward direction ,the finger curls in anticlockwise direction and when direction of current reverses ,then the direction of field also reverses .
Answer:
680 J
Explanation:
Mechanical energy = potential energy + kinetic energy
ME = PE + KE
ME = mgh + ½ mv²
ME = (77.1 kg) (9.8 m/s²) (0.90 m) + ½ (77.1 kg) (0 m/s)²
ME = 680 J
Explanation :
(1) Involuntary muscles are the muscles that are not controlled by our will.
(2) Tendons are the connective tissues that join the muscle to bones. Tendons are tissues that have fibers.
(3) Cardiac muscle is also involuntary muscles. For example heart muscle. It shows contraction and relaxation throughout life.
(4) Voluntary muscle is the muscles that are not controlled by our will.
(5) Biceps are the arm muscles.
Hence, this the required explanation as per options.
Answer:
Explanation:
Given
Each student exert a force of 
Let mass of car be m
there are 18 students who lifts the car
Total force by 18 students 
therefore weight of car 
mass of car 

(b)
Answer:
Are you trying to calculate the net force?
If so, it would be 3 N Up.
This is because the 15 N forces from the left and right cancel out, leaving only the upwards 15 N force, and the 12 N force. However, we have to subtract 12 from 15, leaving the final net force to be 3 N Up.
Let me know if this helps!