Answer: <u>Option A: </u>The gas and food are examples of energy.
Explanation:
Work and energy are inter-related. Energy is required to do the work. An equal amount of energy is converted into work. Work and energy have same units. The SI unit is Joule.
The gas and food are sources of energy. They act as fuel. This energy is utilized to perform work. The gas is used to run the car. The food is metabolized inside the body which is a source of energy and utilized to perform every day work.
Hence, The gas and food are examples of energy.
Gravitational Potential Energy, GPE = mgh
Where m is your mass in kg, g is acceleration due to gravity = 9.8 m/s², and h is the height in m.
The only value that be controlled here is the height h. The mass is constant, and acceleration due to gravity at that place is constant.
But h can be varied.
Hence to increase the gravitational potential energy between yourself and Earth is to increase the height h.
This can be done by climbing up a table, or climbing up a building through the stairs, or by using a lift.
Answer:
9.8 m/s
Explanation:
The work done by the force pushing the cart is equal to the kinetic energy gained by the cart:
where
W is the work done
is the final kinetic energy of the cart
is the initial kinetic energy of the cart, which is zero because the cart starts from rest, so we can write:
But the work is equal to the product between the pushing force F and the displacement, so
So, the final kinetic energy of the cart is 480 J. The formula for the kinetic energy is
(1)
where m is the mass of the cart and v its final speed.
We can find the mass because we know the weight of the cart, 98.0 N:
Therefore, we can now re-arrange eq.(1) to find the final speed of the cart:
In a parallel circuit, the total power supply current is the sum of the
currents through all of the individual branches.
The output current (not the voltage) of the power supply is 5 A.
So the individual currents in the circuit branches is 5 A.
The current through the first 2 resistors is (1 + 0.5) = 1.5 A.
So the current through the 3rd resistor is (5 - 1.5) = <u>3.5 A</u>.
Answer:
charge Qint = 7.17 10⁻⁴ C
Explanation:
For this problem we must use Gauss's law
F = ∫ E. dA = Qint / εₙ
let's form a Gaussian surface that is parallel to the surface, for example, a Cube. As the field is vertical and perpendicular to the surface, the field lines and the area vector are parallel whereby the scalar product is reduced to an ordinary product.
Φ = E A = Qint / ε₀
A = 1 km² (1000 m / 1km)² = 1 10⁶ m²
We can calculate the charge
Qint = E A ε₀
Qint = 81 1 10⁶ 8.85 10⁻¹²
Qint = 7.17 10⁻⁴ C
