A bag is dropped from a hovering helicopter. After 42.4s, calculate the bag’s displacement.

A ball is thrown up at 30m/s from the ground. What is it s maximum height? How long did it take?

Rzqust [24]

Answer:

Maximum height reached by the ball thrown up at 30m/s is 3.06 seconds and the height reached is 45.9 meters

Explanation:

Given:

Initial velocity $u=30 \mathrm{m} / \mathrm{s}$

To find :

maximum height =?

time taken=?

Solution:

Step 1:Finding the time taken to reach the highest point:

The velocity of the ball at its highest ,final velocity v=0

Using the formula,

$v=u+a t$

Where a is acceleration due to gravity.Its value is $-9.8 m / s^{2}$

Substituting the values:

$0=30+(-9.8) t$

$-30=(-9.8) t$

$t=\frac{30}{9.8}$

$t=3.06 \mathrm{seconds}$

Step 2: finding the highest point

Using the formula

$v^{2}-u^{2}=2 a s$

where

s is the maximum highest.

Substituting values

$0^{2}-(30)^{2}=2(-9.8) s$

$0-900=(-19.6) s$

$-900=(-19.6) s$

$s=\frac{900}{19.6}$

$s=45.9 \text { meters }$

Result:

Thus the maximum height reached is 45.9 meters in 3.06 seconds

3 0

3 years ago

Read 2 more answers

C. You push a sled of mass 15 kg across the snow with a force of 180 N for a distance of 2.5 m. There is no friction. If the sle

Svetllana [295]

Explanation:

7.7 m/s

1st determine you subject slade to you have a mass of 15 kg being subjected to a force of 180N

so.

180N/15kg=180(kg m)/s^2/15kg=12 ms^2

now determine how long u pushed it

d=0.5 A T^2

sutable the known values getting

2.5 m = 0.5 12 ms^2 T^2

2.5m= 0.6 ms^2 T^2

0.41667 s^2=T^2

0.645497224s=T

the velocity multiply the time by the acceleration giving

0.645497224 s 12 ms^2 =7.745966692 ms.

after rounding the 2 significant u get 7.7 ms

4 0

3 years ago

You are creating waves in a rope by shaking your hand back and forth. Without changing the distance your hand moves, you begin t

scoundrel [369]

Answer:

Amplitude - remains the same

Frequency - increases

Period - decreases

Velocity - remains the same.

Explanation:

The amplitude of the wave remains the same since you are not changing the distance your hand moves and the amplitude of the wave depends on how much distance your hand covers while moving.

The frequency of your wave increases since now you are moving your hand more number of times in the same period i.e. your hand is moving faster in one second. So, the frequency of your wave increases.

The period is the time taken by the wave to travel a certain distance. Since your hand is now moving faster, the wave will travel faster and will take less time to cover the same distance hence, we can say that its period will decrease.

The velocity of a wave depends on the medium in which it is travelling. Your wave was previously travelling in air and the new wave is also travelling in the same medium so the velocity of the wave remains unchanged.

7 0

3 years ago

At the periphery of a hurricane the air is ____, and several kilometers above the surface, in the eye, the air is ____.

tatuchka [14]

At the periphery of a hurricane the air is sinking, and several kilometers above the surface, in the eye, the air is sinking.

6 0

4 years ago

Steel is very stiff, and the Young's modulus for steel is unusually large, 2.0×1011 N/m2. A cube of steel 25 cm on a side suppor

TEA [102]

Answer:

Force (normal) = 833.85 N Compression = 1.67 x 10⁻⁸ m

Explanation:

Given data Young's Modulus (Y) = 2 x 10¹¹ N/m², Length of one side of cube = 25 cm = 0.25 m, mass of load = 85 kg

Normal force is the force exerted upon an object that is in contact with another stable object. This force would be applied by the surface onto the object in the same vector and is used to keep the object stable while it rests on a surface.

We know from Newton's Second Law that

F = ma where m is the mass and a is the acceleration (in this case due to gravity) hence, the normal opposing force to the load applied by the surface would be equal to the force applied on the surface by the weight of the load on the surface, So

F (normal) = M (load) x a = 85 x 9.81 = 833.85 N

Compression is the change in length of an object by the exertion of force upon it. Using the Young's Modulus formula we can find this change in the cube of steel. The Young's Modulus is given by

Y = (F/A)/(ΔL/L), where Y is the Young's Modulus, F is the Force being applied on the object, A is the cross sectional area on which the said force is applied, ΔL is the change in length due to said force being applied and L is the original Length of the side of the cross sectional area.

Solving this for ΔL, we can re- arrange the equation

ΔL = (F x L)/(Y x A) since area of square is L x L we can simplify the equation to get

ΔL = (F)/(Y x L), substitute the values

ΔL = (833.85)/(2 x 10¹¹ x 0.25) = 1.67 x 10⁻⁸m

6 0

4 years ago