Newton's first law says that an object at rest will stay at rest, while an object in motion will stay in motion unless acted upon by an outside force.
A great example of this is a ball sitting on the ground. The ball will not move until some force is used on it, rather that be you kicking it, the wind blowing it, etc. Once that force is used against it, the ball will continue to move until gravity, air resistance, a friction bring it to a stop.
Answer is C. Because protons and neutrons are more massive then electrons so that means A and b and C are not right
Answer:
The magnitude of the force that the 6.3 kg block exerts on the 4.3 kg block is approximately 41.9 N
Explanation:
Forces on block 4.3 kg are:
63N to the right and R21 (contact force from the 6.3 kg block) to the left
Net force on 4.3 kg block is: 63 N - R21
Forces on the 6.3 kg block are:
R12 to the right (contact force from the 4.3 kg block) and 11 N to the left.
So net force on the 6.3 kg block is: R12 - 11 N
According to the action-reaction principle the contact forces R21 and R12 must be equal in magnitude (let's call them simply "R").
Then, since the blocks are moving with the SAME acceleration, we equal their accelerations:
a1 = (63 N - R)/4.3 = (R - 11 N)/6.3 = a2
solve for R by cross multiplication
6.3 (63 - R) = 4.3 (R - 11)
396.9 - 6.3 R = 4.3 R - 47.3
369.9 + 47.3 = 10.6 R
444.2 = 10.6 R
R = 444.2 / 10.6
R = 41.90 N
This is a problem that can be solved using free-fall motion analysis. Since the displacement (2.9m) is given, we can use the following equation to solve for the impact speed:
V^2 = 2gh
V = sqrt (2*9.8*2.9)
V = 7.54 m/s
