Ask question

Ask question

All categories

3 years ago

6

A competitive diver executes a double somersault with a twist from a platform. Her height above the water t seconds after leavin

g the board is given in feet by h = − 16 t 2 + 0 t + 16 How long does she have to complete her somersault before entering the water?

1 answer:

GarryVolchara [31]3 years ago

7 0

Answer:

One second

Explanation:

Her height above water as function of time after leaving the board is:

$h(t)=-16t^2 +0t+ 16$

When she enters the water the height above the board is zero so h(t)=0, using that on (1):

$0=-16t^2 +0t+ 16$

solving equation for t:

$16t^2=16$

$t^2=1$

$t=\sqrt{1}=1$ s

Mathematically there're in fact two possible values for t, -1 and 1 but because we're talking of time negative sign has no physical sense then we only use 1.

You might be interested in

Gold has a density of 19.32 g/cm 3 . If you cut a piece of gold in half, the density of each piece will be

maksim [4K]

Answer:

See Explanation

Explanation:

The density of a substance is an intrinsic property. Intrinsic properties are properties that are characteristic of a material. It does not depend on the amount of substance present.

Since density is an intrinsic or intensive property, If you cut a piece of gold in half, the density of each piece will still be 19.32 g/cm 3 because density does not depend on the size of the gold piece.

3 0

3 years ago

In which situation is the maximum possible work done?

mina [271]

A) When the angle between the Force (F) and Displacement (x) is 0°, because, Work done (W) is directly proportional to the Cosine of the Angle between the Force applied and the resultant displacement of the subject.
W = F•x cos ∅
If ∅ = 0°,
W = F•x ===> Maximum Work Done.
If ∅ = 45°,
W = F•x/√2
If ∅ = 90°,
W = 0
If ∅ = 180°,
W = –F•x ===> Minimum Work Done.

7 0

3 years ago

2. A jack exerts a vertical force of 4.5 X 103

skad [1K]

Correct Question:-

A jack exerts a vertical force of 4.5 × 10³

newtons to raise a car 0.25 meter. How much

work is done by the jack?

$\\ \\$

Given :-

$\star \sf \small force = 4.5 \times {10}^{3} \: newton$

$\star \sf \small distance = 0.25 \: meter$

$\\ \\$

To find:-

$\sf \star \: work = \: ?$

$\\ \\$

Solution:-

we know :-

$\bf \dag \boxed{ \rm work = force \times distance}$

$\\ \\$

So:-

$\dashrightarrow \sf work = force \times distance$

$\\ \\$

$\dashrightarrow \sf work = (4.5 \times 1 {0}^{3} ) \times 0.5 \\$

$\\ \\$

$\dashrightarrow \sf work = (4.5 \times 1 {0}^{3} ) \times \frac{0 \cancel.5}{10} \\$

$\\ \\$

$\dashrightarrow \sf work = (4.5 \times 1 {0}^{3} ) \times \frac{5}{10} \\$

$\\ \\$

$\dashrightarrow \sf work = (4.5 \times 1 {0}^{3} ) \times \cancel \frac{5}{10} \\$

$\\ \\$

$\dashrightarrow \sf work = \dfrac{4\cancel.5}{10} \times 1 {0}^{3} \times \dfrac{1}{2} \\$

$\\ \\$

$\dashrightarrow \sf work = \dfrac{45}{10} \times 1 {0}^{3} \times \dfrac{1}{2} \\$

$\\ \\$

$\dashrightarrow \sf work = \dfrac{45}{10 {}^{0} } \times 1 {0}^{3 - 1} \times \dfrac{1}{2} \\$

$\\ \\$

$\dashrightarrow \sf work = \dfrac{45}{10 {}^{0} } \times 1 {0}^{2} \times \dfrac{1}{2} \\$

$\\ \\$

$\dashrightarrow \sf work = \dfrac{45}{1} \times 1 {0}^{2} \times \dfrac{1}{2} \\$

$\\ \\$

$\dashrightarrow \sf work = \dfrac{45 \times 10 \times \cancel{10}}{ \cancel2} \\$

$\\ \\$

$\dashrightarrow \sf work = \dfrac{45 \times 10 \times 5}{ 1} \\$

$\\ \\$

$\dashrightarrow \sf work =225 \times 10$

$\\ \\$

$\dashrightarrow \bf work =\red{2250\: joule}$

5 0

3 years ago

Question 4 Unsaved If element X has 93 protons, how many electrons does it have? Your Answer:

9966 [12]

It have 93 electrons

8 0

4 years ago

Which label belongs in the area marked X? Current Magnetic field Solenoid Force on wire

crimeas [40]

when we need to represent the magnetic field in a specific region where it is given that magnetic field lines are perpendicular to the plane and going inside the plane then we always use the concept of representation by "X"

here this symbol represents that field lines are going into the plane

it is also the uniform magnetic field always

so the correct answer would be

<u>Magnetic Field</u>

8 0

3 years ago

Read 2 more answers