D. 128.25 because force=mass x acceleration
It is customary to work in SI units.
Calculate the volume of the concrete.
V = 3.7*2.1*5.8 cm³ = 45.066 cm³ = 45.066 x 10 ⁻⁶ m³
The mass is 43.8 g = 43.8 x 10⁻³ kg
The density is mass/volume.
Density = (43.8 x 10⁻³ kg)/(45.066 x 10⁻⁶ m³) = 971.9 kg/m³
Answer: 971.9 kg/m³
Answer:
F = 768 N
Explanation:
It is given that,
Speed of the elevator, v = 3.2 m/s
Grain drops into the car at the rate of 240 kg/min, 
We need to find the magnitude of force needed to keep the car moving constant speed. The relation between the momentum and the force is given by :


Since, the speed is constant,



F = 768 N
So, the magnitude of force need to keep the car is 768 N. Hence, this is the required solution.
The chemical energy of petrol is converted to heat energy on combustion. The heat energy is converted to kinetic energy by the use of internal combustion engines in vehicles. The law of conservation of energy is maintained in each process.
<h3>What is kinetic energy?</h3>
The kinetic energy of an object is associated with its motion. It can be related to the mass and velocity as
K.E = 1/2 mv²
Given is a diagram of energy conversion due to combustion.
The chemical energy of petrol is converted to heat energy on combustion. The heat energy is converted to kinetic energy by the use of internal combustion engines in vehicles.
The law of conservation of energy states that the energy can neither be created nor destroyed. It can be only converted to one form to the other.
In the given process, the mass decreases but energy remains the same in all forms of energy.
Hence, the law of conservation of energy is maintained in each process
Learn more about kinetic energy.
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“a point at which rays of light, heat, or other radiation meet after being refracted or reflected.” Meaning multiple light rays or heat (and other forms of radiation) are all being refracted or reflecting to a certain point