Answer:
Final speed after 2 seconds = 34.6 m/s
Explanation:
Given:
Initial speed of coin (u) = 15 m/s
Time taken = 2 seconds
Find:
Final speed after 2 seconds
Computation:
Gravitational acceleration of earth = 9.8 m/s²
Using first equation of motion;
v = u + at
or
v = u + gt
where,
v = final velocity
u = initial velocity
g = Gravitational acceleration
t = time taken
v = 15 + 9.8(2)
v = 15 + 19.6
Final speed after 2 seconds = 34.6 m/s
You use the equation kinetic energy = 1/2 mass X velocity^2 so your answer is 25000J.
As we know that efficiency of engine is given as

also we know that

given that

efficiency = 21%
now we have




now we have

Answer:
e. the number of active motor units increases.
Explanation:
There is a direct relationship between the number of active motor units and the grip strength in a given scenario. <em>For example, increase in the grip strength leads to increase in the number of active motor units. In the other-hand, the decrease in grip strength leads to the decrease in the number of active motor units.</em>