HEEELLLPPPP MMEEEEEEEE! please

A skydiver has jumped out of a plane and is falling faster and faster. what forces are present in this situation

kompoz [17]

Gravity and air resistance

i took the test and got 100%

5 0

3 years ago

A crane raises a crate with a mass of 150 kg to a height of 20 m. Given that

Virty [35]

Answer:

$\boxed {\boxed {\sf 29,400 \ Joules}}$

Explanation:

Gravitational potential energy is the energy an object possesses due to its position. It is the product of mass, height, and acceleration due to gravity.

$E_P= m \times g \times h$

The object has a mass of 150 kilograms and is raised to a height of 20 meters. Since this is on Earth, the acceleration due to gravity is 9.8 meters per square second.

m= 150 kg
g= 9.8 m/s²
h= 20 m

Substitute the values into the formula.

$E_p= 150 \ kg \times 9.8 \ m/s^2 \times 20 \ m$

Multiply the three numbers and their units together.

$E_p=1470 \ kg*m/s^2 \times 20 m$

$E_p=29400 \ kg*m^2/s^2$

Convert the units.

1 kilogram meter square per second squared (1 kg *m²/s²) is equal to 1 Joule (J). Our answer of 29,400 kg*m²/s² is equal to 29,400 Joules.

$E_p= 29,400 \ J$

The crate has <u>29,400 Joules</u> of potential energy.

7 0

2 years ago

An investigator collects a sample of a radioactive isotope with an activity of 490,000 Bq.48 hours later, the activity is 110,00

Daniel [21]

Answer:

The correct answer is "22.27 hours".

Explanation:

Given that:

Radioactive isotope activity,

= 490,000 Bq

Activity,

= 110,000 Bq

Time,

= 48 hours

As we know,

⇒ $A = A_0 e^{- \lambda t}$

or,

⇒ $\frac{A}{A_0}=e^{-\lambda t}$

By taking "ln", we get

⇒ $ln \frac{A}{A_0}=- \lambda t$

By substituting the values, we get

⇒ $-ln \frac{110000}{490000} = -48 \lambda$

⇒ $-1.4939=-48 \lambda$

$\lambda = 0.031122$

As,

⇒ $\lambda = \frac{ln_2}{\frac{T}{2} }$

then,

⇒ $\frac{ln_2}{T_ \frac{1}{2} } =0.031122$

⇒ $T_\frac{1}{2}=\frac{ln_2}{0.031122}$

$=22.27 \ hours$

3 0

2 years ago

Taste and smell would be considered

natka813 [3]

One of your 5 senses because your 5senses are hearing, smelling, seeing, taste, touching

8 0

2 years ago

A block of mass 14.9 kg is pulled to the right by an applied force of 39.4 N. If it moves with constant velocity, how much frict

lakkis [162]

The frictional force is 39.4 N

Explanation:

We can solve this problem by applying Newton's 2nd law of motion: in fact, the net force acting on the block is equal to the product between its mass and its acceleration. So we can write

$\sum F = ma$