Answer:
Newton's third law is: For every action, there is an equal and opposite reaction.
Explanation:
The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object.
-- As far as we know, the forces on the wheelbarrow are balanced.
-- That tells us that the net force on the wheelbarrow is zero, just
as if there were no forces acting on it at all.
-- That tells us that the wheelbarrow's acceleration is zero ... its
speed and direction of motion are not changing.
-- That tells us that the wheelbarrow is moving in a straight line
at a constant speed. It's very possible that relative to us, the speed
may be zero, but we can't tell that from the given information.
<span>Both electric and magnetic fields exert body forces, meaning they act from a distance. The like charges and poles in both repel; positive charge repels positive and the north pole repels the north pole. For both, the opposite poles/charges attract. Finally, only magnetic fields have poles, and there are two poles, namely the south and north, so they are dipolar.
The diagram that represents all of this information correctly is the third.</span>
Answer:
k = 1 700.7 N/m
v0 = 9.8 m/s^2
Explanation:
Hello!
We can answer this question using conservation of energy.
The potential energy of the spring (PS) will transform to kinetic energy (KE) of the ball, and eventually, when the velocity of the ball is zero, all that energy will be potential gravitational (PG) energy.
When the kinetic energy of the ball is zero, that is, when it has reached its maximum heigh, all the potential energy of the spring will be equal to the potential energy of the gravitational field.
PS = (1/2) k x^2 <em>where x is the compresion or elongation of the spring</em>
PG = mgh
a)
Since energy must be conserved and we are neglecting any energy loss:
PS = PG
Solving for k
k = (2mgh)/(x^2) = ( 2 * 1.7 * 9.81 * 4.9 Nm)/(0.31^2 m^2)
k = 1 700.7 N/m
b)
Since the potential energy of the spring transfors to kinetic energy of the ball we have that:
PS = KE
that is:
(1/2) k x^2 = (1/2) m v0^2
Solving for v0
v0 = x √(k/m) = (0.31 m ) √( 1 700.7 N/m / 1.7kg)
v0 = 9.8 m/s^2
