Answer:
10392.30N
Explanation:
We proceed by computing the individual force exerted by the boats
For the first boat
The angle is 30 degree to the vertical
Hence
Force = F cos θ
F=6000 cos 30
F=6000*0.866
F=5196.15 N
Since the boats are two and also at the same angle and also exerting the same force
The Net force = 2*5196.15
Net force=10392.30N
Answer: The increase in temperature of the nail after the three blows is 8.0636 Kelvins. The correct option is (d).
Explanation:
Kinetic energy of the hammer ,K.E.=

Half of the kinetic energy of the hammer is transformed into heat in the nail.
Energy transferred to the nail in one blow =

Total energy transferred after 3 blows,Q =
Mass of the nail = 15 g = 0.015 kg
Change in temperature =
Specif heat of the steel = c = 448 J/kg K



The increase in temperature of the nail after the three blows is 8.1 Kelvins.Hence, correct option is (d).
direction ................................................................
The object will continue moving in a straight line at constant speed.