Answer:
T = 16.72 N
Explanation:
When the object is swung in a circular path, and in a vertical plane, there are two forces external to the object acting on it at any time: the gravity (which is always downward) and the tension in the string (which always points towards the center of the circle).
At the bottom of the circle, the tension is directly upward, so these two forces, are opposite each other, and the difference between them is the centripetal force , which at this point, keeps the object swinging in a circle.
This is the point of the trajectory where T is maximum.
We can apply Newton's 2nd Law, choosing an axis vertical (y-axis) being the upward direction the positive one, as follows:
T- m*g = m*a
The acceleration, at the bottom of the circle, is only normal (as there are no forces in the horizontal direction) , and is equal to the centripetal acceleration, as follows:
ac = v² / r = ω²*r⇒ T- m*g = m*ω²*r
Replacing by the givens, we can solve for T as follows:
T = m* (ω²*r+g) = 0.4 kg*((8.00)² rad/sec²*0.5m)+9.8 m/s²) = 16.72 N
Answer:
- Squeezing of a plastic bottle changes the shape of the bottle.
- Deformation of clay by pressing it between the two hands
- stretching of rubber band
hope it becomes helpful to you ☺️☺️
good luck
Answer:
1. The reason why nichrome wire is used in a heater is due to the properties of nichrome which makes it a material of choice for heating application including;
i) The cost of manufacture of nichrome is low
ii) Nichrome has both high mechanical and creep strength, and therefore is suitable for installation and use in a wide setting
iii) Nichrome has a high resistance to electron flow, making it a good electrical heating element
iv) Nichrome has a high resistance to oxidation, such that it can be reused several times as a heater
v) The high ductility of nichrome allows it to be stretched and drawn around different vessels with contents to which heat is to be supplied
2. Copper wire is not used in heaters because according to Joule's law, the heat produced from the flow of electric current, 'I', through a material having a resistance, 'R', for a time, 't', is proportional to I²·R·t, and copper has a very low resistance, 'R', to the flow of electric current, and therefore, will not produce sufficient heat required at a given current level
Explanation:
Answer:
The change in momentum of the car is 30,000 kg m/s
Explanation:
Given,
The force exerted on the car to slow down, F = 7500 N
The time period of force, t = 4 s
The rate of change of momentum of the object is equal to the force acting on it.
Therefore,
<em> (mv - mu) / t = F</em>
Where v and u are the final and initial velocity of the car. The change in momentum of the car,
mv - mu = F x t
= 7500 x 4
= 30,000 kg m/s
Hence the change in momentum of the car is 30,000 kg m/s
