A woman tosses a ball straight upward at 25m/s how long is the ball in the air

What type of force keeps the Earth in orbit around the Sun?

faust18 [17]

The answer is the suns gravity

5 0

3 years ago

A physics professor did daredevil stunts in his spare time. His last stunt was an attempt to jump across a river on a motorcycle

tatiyna

Answer:

a) 17.8 m/s

b) 28.3 m

Explanation:

Given:

angle A = 53.0°

sinA = 0.8

cosA = 0.6

width of the river,d = 40.0 m,

the far bank was 15.0 m lower than the top of the ramp h = 15.0 m,

The river itself was 100 m below the ramp H = 100 m,

(a) find speed v

vertical displacement

$-h= vsinA\times t-gt^2/2$

putting values h=15 m, v=0.8

$-15 = 0.8vt - 4.9t^2$ ............. (1)

horizontal displacement d = vcosA×t = 0.6×v ×t

so v×t = d/0.6 = 40/0.6

plug it into (1) and get

$-15 = 0.8\times40/0.6 - 4.9t^2$

solving for t we get

t = 3.734 s

also, v = (40/0.6)/t = 40/(0.6×3.734) = 17.8 m/s

(b) If his speed was only half the value found in (a), where did he land?

v = 17.8/2 = 8.9 m/s

vertical displacement = $-H =v sinA t - gt^2/2$

⇒ $4.9t^2 - 8.9\times0.8t - 100 = 0$

t = 5.30 s

then

d =v×cosA×t = 8.9×0.6×5.30= 28.3 m

3 0

2 years ago

You are given five transparent objects: a calcite crystal, a diamond, a piece of window glass, a sample of quartz, and a piece o

blsea [12.9K]

Answer:

Explanation:

The calcite Crystal can be identified by carrying out an acid test on it. This is done by bringing it in contact with a weak acid which cause crack in it structure. Hence a little of carbondioxide gas is released.

Since diamond is the hardest object,it can be identified on a Mohs scale. Likewise it can be tested by bringing it in contact with a newspaper, if the letters on the paper are not seen, that shows it is a pure diamond.

Window glass is identified by the code on it.

While Quartz Crystal is identified by scratch test. When it is used to scratch all other softer stones and metal, it leaves mark on them.

5 0

3 years ago

A 10-kilogram mass is sliding along a frictionless floor with an acceleration of 5 meters per second squared. What is the magnit

mart [117]

Answer:

<h3>The answer is 50 N</h3>

Explanation:

The force acting on an object given it's mass and acceleration can be found by using the formula

<h3>force = mass × acceleration</h3>

From the question we have

force = 10 × 5

We have the final answer as

Hope this helps you

5 0

3 years ago

A small block of mass m on a horizontal frictionless surface is attached to a horizontal spring that has force constant k. The b

Rashid [163]

Answer:

$v_{max} = |d|\cdot \sqrt{\frac{k}{m} }$

Explanation:

The maximum speed of the block occurs when spring has no deformation, that is, there is no elastic potential energy, which can be remarked from appropriate application of the Principle of Energy Conservation:

$\frac{1}{2}\cdot k \cdot d^{2} = \frac{1}{2}\cdot m \cdot v^{2}$

$k \cdot d^{2} = m\cdot v^{2}$

$v_{max} = |d|\cdot \sqrt{\frac{k}{m} }$

5 0

3 years ago