If 128 v is required to push 4.00 A of current though a resistor, what is the resistance

An elevator accelerates upward at 2.0 m/s?,

amm1812

Answer:

Force the floor exerts on the passenger is 833 N.

Explanation:

Weight of passenger ( $F_{g}$ ) = mg = 85 × 9.8 N = 833 N

Force the floor exerts on the passenger ( $F_{N}$ ) = ?

For the elevator with the speed as 2.0 m/s the net force is zero, it means that the force is balanced.

i.e. $F_{N}$ = - $F_{g}$ = -mg = 833 N

hence $F_{N}$ is 833 N

If the lift was not at a constant speed i.e. if it had acceleration ( $m/s^{2}$ ) then the case would be different.

4 0

3 years ago

Consider three force vectors Fi with magni- tude 53 N and direction 116º, F2 with mag- nitude 57 N and direction 217°, and F3 wi

Flauer [41]

Answer:

a. Fnet =37.67N

b. The direction = 133.4 from the x axis counter clockwise.

c. Option 2

Explanation:

Given that F1 is 53N at 116°, then it will be at a direction of 116-90=26° in the second quadrant.

Given that F2 is 57N at 116°, then it will be at a direction of 217-180=37° in the third quadrant..

Given that F1 is 71N at 20°, then it is in the first quadrant.

a. Fnet= F1+F2+F3

Fnet= -F1sin26i+F2cos26j-F2cos37i-F2sin37j+F3cos20i+F3sin20j

Fnet= 53sin26i+53cos26j-57cos37i-57sin37j+71cos20i+71sin20j

Resolving the vectors into x and y components.

Fnet= -2.04i+37.62j

Magnitude of the vector

Fnet= √((-2.04)^2+(37.62)^2)

Fnet= 37.67N

Fnet is approximately 38N.

b. Direction of the Fnet.

Angle=arctan(y/x)

Angle=arctan(-37.61/2.04)

Angle= -43.37°

The angle is in the negative x axis and positive y axis.

Then the direction becomes 180-43.37

Therefore, the direction of the net force is 133.37°.

c. The instantaneous velocity of a body is always in the direction of the net force at that instant. Option 2 is correct.

Fnet=ma

Fnet= mv/t

So the velocity is in the direction of the Fnet.

3 0

3 years ago

Three out of four crashes happen at a speed of __________ miles per hour or less.

Nitella [24]

<span>The answer is 45 miles per hour or even less. Most crashes occur at a speed of 45 miles per hour or even less, and most of these accidents occur close to our homes. These crashes may also be caused by different factors, such as being drunk or sudden occurrences that are not controllable, which is why it is best to precede with caution when driving at crowded areas.</span>

5 0

3 years ago

The bob of a pendulum swings back and forth with a total mechanical energy of 300 J. What is the kinetic energy of the bob when

zhenek [66]

at the lowest point in the trajector, the kinetic energy of the bob is 300 J.

Explanation:

The total mechanical energy of the bob at any point of its motion is given by

$E=KE+PE$

Where

$KE=\frac{1}{2}mv^2$ is the kinetic energy, where

m is the mass of the bob

v is its speed

$PE=mgh$ is the gravitational potential energy, where

g is the acceleration of gravity

h is the height of the bob, measured with respect to the lowest point of the trajector

In absence of friction, the total mechanical energy E remains constant. So we have:

- When the bob swings upward, the PE increases (because h increases) and the KE decreases (so the speed decreases). At the highest point in the trajector, the speed of the bob is zero (v=0), so its KE is also zero and all the mechanical energy is potential energy: U = 300 J

- When the bob swings downward, the PE decreases (because h decreases) and the KE increases (so the speed increases). At the lowest point in the trajectory, the height has become zero (h=0), so the PE is zero and all the mechanical energy is kinetic energy: KE = 300 J

Therefore, at the lowest point in the trajector, the kinetic energy of the bob is 300 J.

Learn more about kinetic energy:

brainly.com/question/6536722

#LearnwithBrainly

4 0

3 years ago

An astronaut is taking a space walk near the shuttle when her safety tether breaks. what should the astronaut do to get back to

sergeinik [125]

The best way in handling in this situation is that in order for the astronaut to be able to get back to the shuttle is that he or she should take an object from his or her tool belt and to be thrown out away from the shuttle. This will allow her to weight lightly and safely return to the shuttle and would be easier for his or her to do so.

3 0

3 years ago