Answer:
Explanation:
Gravity pulls everything down at the same rate of 9.8 m/s/s. If you're looking for the normal force, which is the same as the weight of the object, we'll find that, just in case.
w = mg which says that the normal force/weight of an object is equal to its mass times the pull of gravity:
w = 4.0(9.8) so
w = 39N
Answer: Option (d) is correct.
Explanation:
Given, 1,152 British thermal units
1 British thermal unit = 1055.06 joules
So, in 1,152 British thermal units there will be :

Hence, from the given options the closest answer is of option (d). So, option (d) is correct.
The best answer is letter (A) a double pulley system. Atwood Machine is normally used as a measurement in balancing to object to verify the mechanical law of motion with constant acceleration.
Answer;
D. rocket engines are not dependent on oxygen from the air.
Explanation;
-Jet engines and rockets work on the same principle. They produce thrust through an internal pressure difference and, as explained by Newton’s Third Law of Motion, eject exhaust gases in an equal and opposite direction.
-The main difference between them is that jets get the oxygen to burn fuel from the air and rockets carry their own oxygen, which allows them to operate in space.
Additionally, Jet engines have two openings (an intake and an exhaust nozzle). Rocket engines only have one opening (an exhaust nozzle).