Gravitational potential energy is defined as the amount of energy an object possesses at a given height above the Earth's surface. The equation for gravitational energy is E = mgh. Here, m is the mass of the object, g is the acceleration due to gravity, and h is the height above the Earth's surface. Hence, the answer is E = 2000kg x 9.81m/s^2 x 2m = 39240 Joules.
Answer:
94.67 N
Explanation:
Consider a free body diagram with force, F of 41 N applied at an angle of 37 degrees while the weight acts downwards. Resolving the force into vertical and horizontal components, we obtain a free body diagram attached.
At equilibrium, normal reaction is equal to the sum of the weight and the vertical component of the force applied. Applying the condition of equilibrium along the vertical direction.

Substituting 70 N for W, 41 N for F and
for 37 degrees
N=70+41sin37=94.67441595 N and rounding off to 2 decimal places
N=94.67 N
Answer:
a) It reduces the kinetic energy loss of the stunt person.
The heat required to convert the unknown substance X from one phase to another is 1600 J times the specific heat of that substance.
Explanation:
The heat energy required to convert a substance or to heat up or increase the temperature of a substance can be obtained from the specific heat formula.
As per this formula, the heat energy applied should be equal to the product of mass of the substance with temperature gradient and also with specific heat of the substance. Basically, the heat provided to increase or convert a substance should be more than the specific heat of the substance.

Since, here the mass of the substance X is given as m = 20g and the temperature change is given from -10°C to 70°C.
Then ΔT = (70-(-10))=70+10=80°C.
As the substance is unknown, the specific heat of that substance can also not be determined. Hence keep it as C.

Q = 1600C J
Thus, the heat required to convert the unknown substance X from one phase to another is 1600 J times the specific heat of that substance.
Answer:
Explanation:
When a lightning bolt travels from the cloud to the ground it actually opens up a little hole in the air, called a channel. Once then light is gone the air collapses back in and creates a sound wave that we hear as thunder. The reason we see lightning before we hear thunder is because light travels faster than sound!