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2 years ago

A ball is dropped off a roof. The ball falls for 4 seconds. Just before the ball hits the ground what is its velocity?

Physics

1 answer:

scZoUnD [109]2 years ago

7 0

Answer:

The velocity is 39.24 m/s

Explanation:

The time of fall t = 4 seconds

The initial velocity u = 0 m/s (since the ball is dropped, meaning it starts from rest)

Final velocity v = ?

Using

v = u + gt

where g is the acceleration due to gravity = 9.81 m/s^2

substituting, we'll have

v = 0 + (9.81 x 4)

v = 39.24 m/s

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What is the mass of an object which has a force of 600 N acting on it and is travelling

Paha777 [63]

Answer:

The mass of the object is 40 Kg

Explanation:

Net Force

According to the second Newton's law, the net force exerted by an external agent on an object is:

F = m.a

Where:

a = acceleration of the object.

m = mass of the object.

The mass can be calculated by solving for m:

$\displaystyle m=\frac{F}{a}$

The object has a net force of F=600 N acting on it and travels at $a=15\ m/s^2$ , thus the mas is:

$\displaystyle m=\frac{600}{15}$

m = 40 Kg

The mass of the object is 40 Kg

6 0

2 years ago

A toroidal solenoid has an inner radius of 12.0 cm and an outer radius of 15.0 cm . It carries a current of 1.50 A . Part A How

tensa zangetsu [6.8K]

Answer:

The number of turns is $N = 1750 \ turns$

Explanation:

From the question we are told that

The inner radius is $r_i = 12.0 \ cm = 0.12 \ m$

The outer radius is $r_o = 15.0 \ cm = 0.15 \ m$

The current it carries is $I = 1.50 \ A$

The magnetic field is $B = 3.75 mT = 3.75 *10^{-3} \ T$

The distance from the center is $d = 14.0 \ cm = 0.14 \ m$

Generally the number of turns is mathematically represented as

$N = \frac{2 * \pi * d * B}{ \mu_o * r_o }$

Generally $\mu_o$ is the permeability of free space with value

$\mu_o = 4\pi * 10^{-7} \ N/A^2$

$N = \frac{2 * 3.142 * 0.14 * 3.75 *10^{-3} }{ 4\pi * 10^{-7} * 0.15 }$

$N = 1750 \ turns$

5 0

2 years ago

A submarine is 2.84 102 m horizontally from shore and 1.00 102 m beneath the surface of the water. A laser beam is sent from the

xxMikexx [17]

Answer:

468 m

Explanation:

So the building and the point where the laser hit the water surface make a right triangle. Let's call this triangle ABC where A is at the base of the building, B is at the top of the building, and C is where the laser hits the water surface. Similarly, the submarine, the projected submarine on the surface and the point where the laser hit the surface makes a another right triangle CDE. Let D be the submarine and E is the other point.

The length CE is length AE - length AC = 284 - 234 = 50 m

We can calculate the angle ECD:

$tan(\hat{ECD}) = \frac{ED}{EC} = \frac{100}{50} = 2$