Answer:
Explanation:
We know that for circular motion the centripetal acceleration 
is:
where v is the speed and r is the radius.
The centripetal acceleration for the astronaut must be the gravitational acceleration due to the gravity, as there are no other force. So
.
The radius of the orbit must be the radius of the Moon, plus the 270 km above the surface
We can obtain the speed as:
And this is the orbital speed.
Definition: Momentum = (mass) x (speed)
OK. Here we go.
Watch closely:
Divide each side
by 'mass' : <span>Momentum / mass = Speed </span>
Did you follow that ?
Answer:
Action and reaction are equal but act in opposite directions
Answer: work = 1,305kJ
Explanation:
angle= 30°
force= 1,500N
distance= 1,000m
The formula for work is : Work= force x distance, however there is an angle of 30° between the direction of force applied and the direction of motion, therefore force must be decomposed to its value on the horizontal axis which is the direction of motion by using the cosine of the very angle.
W= F×cos(α)×D
W= 1,500×cos (30)×1,000
W= 1,305kJ ( kilojoules)
