Answer:
first of all since the value of mass of the object and force F(horizontal) or the relation between them is not mentioned , so there can be multiple effects and let us study them in cases.
Let us consider that mass of the object is m and the coefficient of friction is the coefficient of static friction of the surface{since friction can be static as well as dynamic} whose value(μ) as is given in the question is 0.2. Since the surface and the force applied are both horizontal so there will be no vertical component of the force applied which means that the normal force is N=weight of the object=mg where g is the acceleration due to gravity(9.8 m/s^2 on average on surface of earth).
Case 1:
When F<=μN. This means that when the value of F is less than or equal to μN then the static friction is equal to F. So the body remains stationary.
Case 2:
When F>μN. This means that when the value of F is greater than μN then the static friction is less than F. So the body starts moving and if the force applied F is constant then the body will start accelerating because coefficient of kinetic friction is less than that of static friction.
Explanation:
The minimum initial velocity that the ball must have for it to reach the top of the hill is 21 m/s. The correct option is D.
<h3>What is mechanical energy?</h3>
The mechanical energy is the sum of kinetic energy and the potential energy of an object at any instant of time.
M.E = KE +PE
A boy is trying to roll a bowling ball up a hill. The friction is ignored. The ball must have to reach the top of the hill with a velocity. The acceleration due to gravity, g = 9.8 m/s²
The conservation of energy principle states that total mechanical energy remains conserved in all situations where there is no external force acting on the system.
M.E bottom of hill = M.E on top of hill
Kinetic energy + Potential energy = Kinetic energy + Potential energy
1/2 mu² + 0 = 0 + mgh
At the top of hill, the velocity will become zero. So, final kinetic energy is zero.
Substituting the values, we have
1/2 x u² = 9.8 x 22.5
u = sqrt [2 x9.8 x 22.5 ]
u= 21 m/s
Thus, the minimum initial velocity that the ball must have for it to reach the top of the hill is 21 m/s.
Learn more about mechanical energy.
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Answer: I only have the answer for A, but still, the answer is 20.07.
- Explanation: Because the number ends in a 15, round to the nearest tenth which is 20. So now the number is 5420.
- To get the Watts (W) you have to take 5420 and divide it by the time in seconds. 4.5 minutes in seconds is 270, so 5420 divided by 270 equals 20.07.
- So 20.07 is the answer.
Kinetic energy is greatest when it passes through the center, lowest point. Potential energy is zero there.
Potential energy is greatest at the left and right ends, where it stops and heads back the other way. Kinetic energy is zero there.
So the pendulum is constantly converting its energy from one state to the other.
Pull it to the side and hold. Energy is all potential. Then let it go.
One complete swing ... to the other side and back to your hand ... does this:
Potential & let it go -> kinetic -> potential -> kinetic -> Potential & catch it.
<span>. . . . . . . . . . . . . . . . . . center . . . . . . . . . . . . center this is sombody elses but i moved here for you
still mark brainlest please if right
</span>
Hello!
We can use Ohm's Law to solve for the potential difference across a resistor given the current and resistance:
![V = iR](https://tex.z-dn.net/?f=V%20%3D%20iR)
V = Potential Difference (? V)
i = Current (1.5 A)
R = Resistance (12 Ω)
Plug in the known values and solve.
![V = (1.5)(12) = \boxed{18 V}](https://tex.z-dn.net/?f=V%20%3D%20%281.5%29%2812%29%20%3D%20%5Cboxed%7B18%20V%7D)