Power is a measure of the rate of energy or work done on a system. It has units of energy per time. In SI, Joules per second and is equal to the units of Watts. So, for an 800 Watts hair straightener, the energy transfer per second would be 800 Joules.
Answer:
K = 1800 kJ
Explanation:
Given that,
The speed of the object, v = 30 m/s
Mass of the object, m = 4000 kg
We need to find the kinetic energy of the object. The formula for the kinetic energy is given by :
![K=\dfrac{1}{2}mv^2\\\\K=\dfrac{1}{2}\times 4000\times 30^2\\\\K=1800000\\\\or\\\\K=1800\ kJ](https://tex.z-dn.net/?f=K%3D%5Cdfrac%7B1%7D%7B2%7Dmv%5E2%5C%5C%5C%5CK%3D%5Cdfrac%7B1%7D%7B2%7D%5Ctimes%204000%5Ctimes%2030%5E2%5C%5C%5C%5CK%3D1800000%5C%5C%5C%5Cor%5C%5C%5C%5CK%3D1800%5C%20kJ)
So, the required kinetic energy is equal to 1800 kJ.
THE BALL'S ACCELERATION IS 130.90![\frac{m}{s}](https://tex.z-dn.net/?f=%5Cfrac%7Bm%7D%7Bs%7D)
Explanation:
According to Newton's second law "the force (F) acting on an object is equal to the mass (m) of an object times its acceleration (a)", meaning that when the soccer player kicks a ball, a force is acting on the ball, therefore increasing it's acceleration
SO FOR CALCULATING THIS WE WILL USE NEWTON LAW,
FORCE = MASS × ACCELERATION
WE ARE GIVEN
FORCE = 57.6N
MASS= .44KG
SO HERE WE APPLYING FORMULA ,WE WILL GET
ACCELERATION = ![\frac{FORCE}{MASS}](https://tex.z-dn.net/?f=%5Cfrac%7BFORCE%7D%7BMASS%7D)
ACCELERATION = ![\frac{57.6N}{.44KG}](https://tex.z-dn.net/?f=%5Cfrac%7B57.6N%7D%7B.44KG%7D)
ACCELERATION =130.90![\frac{m}{s}](https://tex.z-dn.net/?f=%5Cfrac%7Bm%7D%7Bs%7D)
Answer:
6 km/h
Explanation:
V avg = ∆x/∆t = 3km / 30 min ×(60min/1h) = 3 km× 2 /h = 6 km/h
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