How much energy is needed just to boil 5kg of water at 100◦ C?

What evidence of a chemical change is observed when rust forms on iron

bagirrra123 [75]

A non-reversible Acton. A chemical reaction in non-reversible

4 0

3 years ago

A ball is thrown vertically upward from the top of a building 112 feet tall with an initial velocity of 96 feet per second. The

nordsb [41]

Answer:

$t=6.96s$

Explanation:

From this exercise, our knowable variables are hight and initial velocity

$v_{oy}=96ft/s$

$y_{o}=112ft$

To find how much time does the ball strike the ground, we need to know that the final position of the ball is y=0ft

$y=y_{o}+v_{oy}t+\frac{1}{2}gt^{2}$

$0=112ft+(96ft/s)t-\frac{1}{2}(32.2ft/s^{2})t^{2}$

Solving for t using quadratic formula

$t=\frac{-b±\sqrt{b^{2}-4ac } }{2a}$

$a=-\frac{1}{2} (32.2)\\b=96\\c=112$

$t=-0.999s$ or $t=6.96s$

Since time can't be negative the answer is t=6.96s

7 0

3 years ago

A 75 kg man stands in an elevator. What will be the force that the elevator exerts on him when

Over [174]

Answer:

a is the answer I think so

6 0

3 years ago

A footballer kicks a ball at angle teta to horizontal with some initial velocity a) what are the two types of independent motion

Nezavi [6.7K]

a) The motion along the vertical direction and the motion along the horizontal direction.

b) The object remains in the air for a time period of 2usin(θ)/g.

Any object that is thrown in the air when gravity is acting on it is called a projectile. The motion of this projectile is called projectile motion.

When the projectile is thrown in the air at some angle θ, then there are two independent motions taking place at the same time. First is the component of motion along the vertical direction along which gravity acts. Second is the component of motion along the horizontal direction along which the object moves with a constant velocity. No force acts along the horizontal direction. The horizontal motion does not affect the vertical motion and the converse is also true. So these are independent of each other.

The time of flight is the time during which a projectile remains in the air. This time of flight is calculated using the formula,

T=2usin(θ)/g

where T is the time of flight, u is the initial velocity and g is the acceleration due to gravity.

Hence, the object remains in the air for a time period of 2usin(θ)/g.

Learn more about projectile.

brainly.com/question/11049671

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8 0

2 years ago

Marvin uses a long copper wire with resistivity 1.68 x 10^-8 Ω⋅m and diameter 1.00 x 10^−3 m to create a solenoid that has a 3

Mazyrski [523]

Answer with Explanation: