Answer:
20,850 N
Explanation:
We can solve the problem by using second Newton's Law:
where
F is the force
m is the mass
a is the acceleration
In this problem, we have:
m = 70 kg is the mass
is the acceleration (which is negative, because it is a deceleration)
So, we can use the equation above to find the force:
and the negative sign simply means that the force is in the opposite direction to the motion.
a) Remember Newton's second Law:
F = m*a
This means that the forces that is being exerted over an object is equal to the mass of the object times the acceleration that it has.
In this case, in order to hold the mass you need a force with the same magnitude but opposite direction to the gravitational force. The magnitude of this force would be the mass of the object times the gravitactional acceleration:
F = 2kg*9.80665m/s² = 19.6133 N
b) Using again Newton's second Law, we can issolate mass from that equation:
m = F/a
Then, the mass that a force of 1N can support is equal to:
m = 1N/9.80665m/s² = 0.102 kg
C. explicit and implicit :)
Time = (distance) / (speed)
Time = (150 x 10⁹ m) / (3 x 10⁸ m/s) =
50 x 10¹ sec =
<em>500 sec</em> = 8 min 20 sec