Why a hole at the bottom of a ship is more dangerous than the one that is near the surface?

A ball is projected horizontally from the top of a bertical building 25.0m above the ground level with an initial velocity of 8.

kirill115 [55]

Answer:

Solution given:

height [H]=25m

initial velocity [u]=8.25m/s

g=9.8m/s

now;

a. How long is the ball in flight before striking the ground?

Time of flight =?

Now

Time of flight= $\sqrt{\frac{2H}{g}}$

substituting value

= $\sqrt{\frac{2*25}{9.8}}$
=2.26seconds

<h3>the ball is in flight before striking the ground for 2.26seconds.</h3>

b. How far from the building does the ball strike the ground?

Horizontal range=?

we have

Horizontal range=u* $\sqrt{\frac{2H}{g}}$

=8.25*2.26
=18.63m

<h3>The ball strikes 18.63m far from building. </h3>

7 0

3 years ago

Are the units of the formula ma = mv2/2 dimensionally consistent? Select the single best answer.

Vesnalui [34]

To solve the problem we will simply perform equivalence between both expressions. We will proceed to place your units and develop your internal operations in case there is any. From there we will compare and look at its consistency

$ma = \text{Mass}\times \text{Acceleration}$

$ma = kg \cdot \frac{m}{s^2}$

At the same time we have that

$\frac{1}{2}mv^2 = \text{Mass}\times \text{Velocity}^2$

$\frac{1}{2}mv^2 = kg ( \frac{m}{s})^2$

$\frac{1}{2}mv^2 = kg \cdot \frac{m^2}{s^2}$

Therefore there is not have same units and both are not consistent and the correct answer is B.

5 0

4 years ago

The odometer of a car changes from 1048 km to 1096 km in 40

Makovka662 [10]

Answer:

20m/s

Explanation:

it covers 20 metres in a second

3 0

2 years ago

Determine whether each of the statements below is true or false, and place it in the appropriate bin. Objects with equal speeds

lisov135 [29]

Objects with equal speeds definitely have equal velocities. -- FALSE. For equal velocities, they also have to be going in the same direction.

If you are given an object's velocity, you can definitely determine its speed. -- TRUE. If you know the velocity, then you know both the object's speed and its direction.

If you know the distance an object travels, and the time it takes to do so, you can determine the object's velocity. -- FALSE. Knowing the distance and time, you can figure out the object's speed. But if you don't also know the direction it's moving, then you can't say what its velocity is.

If an object moves at constant speed, it must also be moving at constant velocity. -- FALSE. Besides constant speed, it also needs to move in a straight line to have constant velocity. If it turns, its velocity changes, even if its speed doesn't.

If an object moves at constant velocity, it must also be moving at constant speed. -- TRUE. Constant velocity means its speed AND its direction are not changing.

Objects with equal velocities definitely have equal speeds. -- TRUE. If their velocities are equal, then their speeds are equal AND they're moving in the same direction.

After laboring through this one, I'm wondering if there can possibly be any more ways to say the same thing.

7 0

3 years ago

A car accelerates in the +x direction from rest with a constant acceleration of a1 = 1.76 m/s2 for t1 = 20 s. At that point the

alex41 [277]

Answer:

(a) $v_1 = a_1t_1 = 1.76 t_1$

(b) It won't hit

(c) 110 m

Explanation:

(a) the car velocity is the initial velocity (at rest so 0) plus product of acceleration and time t1

$v_1 = v_0 + a_1t_1 = 0 +1.76t_1 = 1.76t_1$

(b) The velocity of the car before the driver begins braking is

$v_1 = 1.76*20 = 35.2m/s$

The driver brakes hard and come to rest for t2 = 5s. This means the deceleration of the driver during braking process is

$a_2 = \frac{\Delta v_2}{\Delta t_2} = \frac{v_2 - v_1}{t_2} = \frac{0 - 35.2}{5} = -7.04 m/s^2$

We can use the following equation of motion to calculate how far the car has travel since braking to stop

$s_2 = v_1t_2 + a_2t_2^2/2$

$s_2 = 35.2*5 - 7.04*5^2/2 = 88 m$

Also the distance from start to where the driver starts braking is

$s_1 = a_1t_1^2/2 = 1.76*20^2/2 = 352$

So the total distance from rest to stop is 352 + 88 = 440 m < 550 m so the car won't hit the limb

(c) The distance from the limb to where the car stops is 550 - 440 = 110 m

8 0

3 years ago

Why a hole at the bottom of a ship is more dangerous than the one that is near the surface?​

Why a hole at the bottom of a ship is more dangerous than the one that is near the surface?