Answer:
625 N
Explanation:
The impulse given to the nail is equal to the change in momentum of the hammer:

where
F is the force exerted by the hammer
is the time of contact
is the mass
is the change in velocity of the hammer
Substituting the data and re-arranging the equation, we can find the force:

Answer:
speaker64
--------
34x
Explanation:
64-34
x
speaker
4
2
4
788
- circuit
voltage
100000
x.34
Sorry but you have no picture shown
Explanation:
(i) Height of tree, h = 4 m
Mass of Ninja, m = 30 kg
The gravitational potential energy on the top branch of the tree is given by :

g is acceleration due to gravity

(ii) If he were at a height of 2 meters from the ground, its potential energy will be :

g is acceleration due to gravity

Therefore, this is the required explanation.