All categories

3 years ago

HELP MEEEEEEEE PLEASEEEE

Physics

1 answer:

Lemur [1.5K]3 years ago

5 0

Answer:

B Explain why the relationship between force and time is important to a helmet designer.

During a collision, a skater will suddenly come to a complete stop. This is a foam of acceleration. A helmet can change the amount of

hope you get a good grade

You might be interested in

A 25 kg circular disk has a diameter of 2.5 feet and a thickness of 2.5 cm. Find the density of the disk in kg/m3. Next, find th

Gre4nikov [31]

Answer:

Assume that $\rm g= 9.81\; N\cdot kg^{-1}$ ; $\rho(\text{Water}) = \rm 1000\;kg\cdot m^{-3}$ .

Density of the disk: approximately $\rm 2.19\times 10^{3}\; kg\cdot m^{-3}$ .

Weight of the disk: approximately $\rm 245\;N$ .

Buoyant force on the disk if it is submerged under water: approximately $\rm 112\; N$ .

The disk will sink when placed in water.

Explanation:

Convert the dimensions of this disk to SI units:

Diameter: $d = \rm 25\; inches = (25\times 0.3048)\; m = 0.762\;m$ .
Thickness $h = \rm 2.5\; cm = (2.5\times 0.01)\; m = 0.025\;m$ .

The radius of a circle is 1/2 its diameter:

$\displaystyle r = \rm \frac{1}{2}\times 0.762\;m = 0.381\; m$ .

Volume of this disk:

$V(\text{disk}) = \pi\cdot r^{2}\cdot h = \pi\times 0.381^{2}\times 0.025 \approx 0.0114009\; m^{3}$ .

Density of this disk:

$\displaystyle \rho(\text{disk}) = \frac{m}{V} = \rm \frac{25\; kg}{0.0114009\; m^{3}} = 2.19\times 10^{3}\;kg\cdot m^{-3}$ .

$\rho(\text{disk}) >\rho(\text{water})$ indicates that the disk will sink when placed in water.

Weight of the object:

$W(\text{disk}) = m\cdot g = \rm 25\times 9.81 = 245.25\; N$ .

The buoyant force on an object in water is equal to the weight of water that this object displaces. When this disk is submerged under water, it will displace approximately $\rm 0.0114009\; m^{3}$ of water. The buoyant force on the disk will be:

$\begin{aligned}F(\text{buoyant force}) &= W(\text{Water Displaced}) \\& = \rho\cdot V(\text{Water Displaced})\cdot g\\ & = \rm 1\times 10^{3}\; kg\cdot m^{-3}\times 0.0114009\; m^{3}\times 9.81\; N\cdot kg^{-1}\\ &\approx \rm 112\; N\end{aligned}$ .

The size of this disk's weight is greater than the size of the buoyant force on it when submerged under water. As a result, the disk will sink when placed in water.

3 0

3 years ago

What is the term for heat transfer because of the movement of electromagnetic waves?

olchik [2.2K]

It is radiation that transfers heat energy through space by electro radiation.

4 0

4 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

#SPJ4

8 0

2 years ago

A steel ball and a wooden ball of the same diameter are released together from the top of a tower. In the absence of air resista

ella [17]

Answer:

False

Explanation:

The steel ball and the wooden ball do not have the same force acting on them because their masses are different. But, they have the same acceleration which is the acceleration due to gravity g = 9.8 m/s².

Using the equation of motion under freefall, s = ut +1/2gt². Since u = 0,

s = 1/2gt² ⇒ t = √(2s/g)

Since. s = height is the same for both objects, they land at the same time neglecting air resistance.

8 0

3 years ago

I need help with the “kinetic and potential energies” for my potential and kinetic energy of a roller coaster

Ann [662]

UP gaining potential
Down Gaining Kinetic

6 0

3 years ago