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3 years ago

When an object falls, its:

Physics

1 answer:

Shkiper50 [21]3 years ago

5 0

Answer:

Option D. is correct.

Explanation:

The object's mechanical energy refers to the sum of the potential and kinetic energies of the object. When an object falls, its potential energy (PE) decreases, and its kinetic energy (KE) increases. The increase in kinetic energy is exactly equal to the decrease in potential energy.

Option D. is correct.

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What is the relationship between the force of gravity between two objects in regard to their mass and the distance between them?

Mashcka [7]

Answer:

Explanation:

5 0

3 years ago

1-A car moves toward east 12km is represented as A and it turns towards south 16km is represented as B. What is the resultant ve

hjlf

1. A-20 km south east

The car's displacement consists of two components into two different directions. Using a system of coordinates in which x represents the east direction and y represents the south direction, the two displacements are:

$d_x = 12 km$ east

$d_y = 16 km$ south

Since the two components are orthogonal to each other, we can find the resultant displacement by using Pythagorean's theorem:

$d=\sqrt{d_x^2+d_y^2}=\sqrt{(12 km)^2+(16 km)^2}=\sqrt{400}=20 km$

and the direction is between the two original directions, so south-east.

2. D. 10 m/s

First of all, we need to calculate the total time the stone took to hit the ground. Since the vertical distance covered is S = 78.4 m, and since the motion is an accelerated motion with constant acceleration g=9.8 m/s^2, we have

$S=\frac{1}{2}gt^2$

From which we find the total time of the fall, t:

$t=\sqrt{\frac{2S}{g}}=\sqrt{\frac{2(78.4 m)}{9.8 m/s^2}}=4 s$

Now we can consider the horizontal motion of the stone: we know that the stone travels for d = 40 m in a time of t = 4 s, therefore the horizontal velocity of the stone is

$v=\frac{d}{t}=\frac{40 m}{4 s}=10 m/s$

3. B=32.32 m

As in the previous problem, we have to calculate the total time it takes for the stone to reach the river first. Since the vertical distance covered is S = 20 m, we have

$t=\sqrt{\frac{2S}{g}}=\sqrt{\frac{2(20 m)}{9.8 m/s^2}}=2.0 s$

And since the stone is traveling horizontally at v = 16 m/s, the horizontal distance covered is

$d=vt=(16 m/s)(2 s)=32 m$

So, the closest answer is B.

5 0

3 years ago

Which statement best describes why some materials are NOT magnetic?

hammer [34]

paired electrons spin in opposite directions cancelling their magnetic fields

3 0

3 years ago

The product of m1m2 in the formula for gravitational force is always

Nataly [62]

Answer:

The correct answer is the second option

Explanation:

The formula in question (for gravitational force) is provided below

F = G.m₁.m₂/r²

Where

F = force of gravity

G = gravity constant (6.674 × 10⁻¹¹ m.kg⁻¹.s⁻²)

m₁ and m₂ = are the masses of the objects

r² = distance between the centers of the two objects

From the above, <u>it can be deduced that m₁ and m₂ are masses and hence can only be positive. Positives multiplied together only gives positive, thus the second option is correct.</u>

8 0

4 years ago

QUESTION 1 If you do 1,000 J of work on a system and remove 500 J of heat from it, what is the change in its internal energy?

Mazyrski [523]

1. U = Q + W
U = -500 + 1000
U = 500 J

2. The first law of thermodynamic is about the law of conservation of energy where energy in should be equal to energy out.

3. It is the windmill that does not transform energy from heat to mechanical instead it is the transforms the opposite.

4. In a heat engine, work is used to transfer thermal energy from a hot reservoir to a cold one.

5. 5.00 × 10^4 J - 2.00 × 10^4 J = 3.00 × 10^4 J

6. To increase the work done, we raise the temperature of the cold reservoir.

7 0

3 years ago

Read 2 more answers