An object cannot remain at rest unless which of the following holds? there are no forces at all exerted on it. there is only one force exerted on it. the net force exerted on it is constant and nonzero. the net force exerted on it is zero. if a block is moving to the left at a constant velocity, what can one conclude? the net force exerted on the block is directed to the left. the net force exerted on the block is zero. there must be no forces at all exerted on the block. there is exactly one force exerted on the block. a block of mass 2kg experiences a force of magnitude 4 newtons directed to the right. what can you say about the block's motion? it must be moving to the left. it could be moving to the left, moving to the right, or be instantaneously at rest. it must be moving to the right. it must be at rest. a block is being pulled along a horizontal frictionless surface by a constant horizontal force. the block must be moving with a constant nonzero acceleration. moving at constant velocity. moving with continuously increasing acceleration. continuously changing direction.

Explanation:

1. An object cannot remain at rest unless the net force exerted on it is zero. It is also known as the Newton's first law of motion. So, the correct option is (D).

2.  If a block is moving to the left at a constant velocity, that means the velocity is same. So, the change in velocity is zero that is acceleration is zero. So, the net force exerted on the block is zero.

3. Mass of the block, m = 2 kg

Force experienced by the block, F = 4 N (towards right)

Since, the force is acting towards right.. So, the block will accelerates towards rest at the rate of 2 m/s². So, It must be moving to the right is the correct option.

4. A block is being pulled along a horizontal friction less surface by a constant horizontal force. Since, the force is constant, the acceleration will be constant. So, the block must be moving with a constant nonzero acceleration is the correct option.

Hence, this is the required solution.

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.