We simply use the formula,

Given, velocity = 4 m per s and distance = 120 m.
Substituting these values, we get
.
Thus, required time for the elevator in order to travel 120 m upwards is 30 s.
<span>This law means that when one object exerts force on another, the same amount of force is exerted on the initial object, but in the opposite reaction. For example, when a billiard ball strikes another ball, the second ball is propelled forward. Simultaneously, the momentum of the first ball is slowed or stopped by opposing force. The amount that the first object is affected by the opposing force depends on the mass and motion of the second object.</span>
The question is incomplete. The complete question is :
To measure the effective coefficient of friction in a bone joint, a healthy joint (and its immediate surroundings) can be removed from a fresh cadaver. The joint is inverted, and a weight is used to apply a downward force F⃗ d on the head of the femur into the hip socket. Then, a horizontal force F⃗ h is applied and increased in magnitude until the femur head rotates clockwise in the socket. The joint is mounted in such a way that F⃗ h will cause clockwise rotation, not straight-line motion to the right. The friction force will point in a direction to oppose this rotation.
Draw vectors indicating the normal force n⃗ (magnitude and direction) and the frictional force f⃗ f (direction only) acting on the femur head at point A.
Assume that the weight of the femur is negligible compared to the applied downward force.
Draw the vectors starting at the black dot. The location, orientation and relative length of the vectors will be graded
Solution :
The normal force represented by N is equal to the downward force,
which is equal in magnitude but it is opposite in direction.
Also the frictional force acts always to oppose the motion because the bone starts moving in a clockwise direction. The frictional force that will be applied to the right direction so that the movement or the rotation at A is opposed.
The peak magnetic field of the electromagnetic wave in the red part of the visible spectrum is 9.67 x 10⁻¹⁰ T.
<h3>Relationship between electric and magnetic field</h3>
The relationship between electric and magnetic field at a given peak electric field is given as;
c = (E₀) / (B₀)
where;
- c is speed of light
- E₀ is the peak electric field
- B₀ is the peak magnetic field
B₀ = E₀ / c
B₀ = (2.9) / (3 x 10⁹)
B₀ = 9.67 x 10⁻¹⁰ T
Thus, the peak magnetic field of the electromagnetic wave in the red part of the visible spectrum is 9.67 x 10⁻¹⁰ T.
Learn more about peak magnetic field here: brainly.com/question/24487261