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3 years ago

Please Help! Question 2 Unsaved

Physics

1 answer:

Ilia_Sergeevich [38]3 years ago

6 0

2. a cruise ship docked in a port

In fact, inertia is the resistance of an object to any change in its velocity/change of its state of motion. The inertia of an object depends only on the mass of the object: the greater the mass, the larger the inertia. In this case, the object with largest mass among the choices is the cruise ship docked in the port, so this is the object with most inertia.

3. gram

Mass represents the quantity of matter inside an object, and it is measured in grams (g). Actually, the SI units of the mass is the kilogram (kg), a multiple of the gram: 1 kg = 1000 g.

4. $m/s^2$

Acceleration is defined as the rate of change of velocity per unit time:

$a=\frac{\Delta v}{\Delta t}$

The change in velocity, $\Delta v$ , is measured in m/s, while the time $\Delta t$ is measured in seconds (s): therefore, the acceleration is measured in

$[a]=\frac{[m/s]}{[s]}=[\frac{m}{s^2}]$

5. Newtons

The Newton (N) is the SI unit used for the force. The force is defined as the product between mass (m) and acceleration (a):

$F=ma$

since the mass is measured in kg and the acceleration in m/s^2, 1 Newton corresponds to

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

6. 1030 N

Given m=1.04 kg (mass of the hockey puck) and $a=987 m/s^2$ (acceleration of the hockey puck), the force needed to accelerate the puck with this acceleration is given by Newton's second law:

$F=ma=(1.04 kg)(987 m/s^2)=1026 N$

which corresponds (approximately) to option C) 1030 N.

7. 520 kg

Given $a=9.71 m/s^2$ (acceleration of the car) and F=5050 N (net force applied on the car), we can find the mass of the car by using again Newton's second law:

$m=\frac{F}{a}=\frac{5050 N}{9.71 m/s^2}=520 kg$

8. 1.00 m/s2

In this case, the net force applied by Amber is F=35 N.

The total mass of the brother+wagon is

$m=32 kg+3 kg=35 kg$

Therefore, we can find the acceleration of the system by using again Newton's second law:

$a=\frac{F}{m}=\frac{35 N}{35 kg}=1.00 m/s^2$

9. forward

This is because of the inertia: in fact, the car (and the groceries inside it) is initially moving forward. When it stops, the groceries inside the car tends to continue moving forward: due to their inertia, they tends to continue their motion with constant speed, until they are stopped by an external force.

10. The tendency of an object with mass to resist a change in its motion.

Inertia is exactly this: the tendency of an object with mass to resist a change in its motion. This means that an object at rest tends to stay at rest, while an object in motion tends to keep its speed. The inertia of an object depends only on its mass: the larger the mass, the greater the inertia.

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Two metal sphere each of radius 2.0 cm, have a center-to-center separation of 3.30 m. Sphere 1 has a chrage of +1.10 10^-8 C. Sp

Leokris [45]

Answer:

A) V = -136.36 V , B) V = 4.85 10³ V , C) V = 1.62 10⁴ V

Explanation:

To calculate the potential at an external point of the spheres we use Gauss's law that the charge can be considered at the center of the sphere, therefore the potential for an external point is

V = k ∑ $q_{i} / r_{i}$

where $q_{i}$ and $r_{i}$ are the loads and the point distances.

A) We apply this equation to our case

V = k (q₁ / r₁ + q₂ / r₂)

They ask us for the potential at the midpoint of separation

r = 3.30 / 2 = 1.65 m

this distance is much greater than the radius of the spheres

let's calculate

V = 9 10⁹ (1.1 10⁻⁸ / 1.65 + (-3.6 10⁻⁸) / 1.65)

V = 9 10¹ / 1.65 (1.10 - 3.60)

V = -136.36 V

B) The potential at the surface sphere A

r₂ is the distance of sphere B above the surface of sphere A

r₂ = 3.30 -0.02 = 3.28 m

r₁ = 0.02 m

we calculate

V = 9 10⁹ (1.1 10⁻⁸ / 0.02 - 3.6 10⁻⁸ / 3.28)

V = 9 10¹ (55 - 1,098)

V = 4.85 10³ V

C) The potential on the surface of sphere B

r₂ = 0.02 m

r₁ = 3.3 -0.02 = 3.28 m

V = 9 10⁹ (1.10 10⁻⁸ / 3.28 - 3.6 10⁻⁸ / 0.02)

V = 9 10¹ (0.335 - 180)

V = 1.62 10⁴ V

6 0

3 years ago

A 190 g rock at 20°C is completely immersed in 600 g of water at 80°C. Which one of the following statements is true right after

Umnica [9.8K]

Rock is completely immersed in hot water. By the second law of thermodynamics, thermal energy or heat is transferred from substance with higher temperature to substance with lower temperature until they come to thermal equilibrium i.e. both at same temperature.

It is given here that rock is at 20°C which is at lower temperature than water at 80°C. ∴Heat or thermal energy flows from water to rock. So, right choice is-

A. The water gives the rock thermal energy and gets no thermal energy in return.

8 0

3 years ago

A uniformly charged sphere has a potential on its surface of 450 V. At a radial distance of 7.2 m from this surface, the potenti

Yakvenalex [24]

Answer:

The radius of the sphere is 3.6 m.

Explanation:

Given that,

Potential of first sphere = 450 V

Radial distance = 7.2 m

If the potential of sphere =150 V

We need to calculate the radius

Using formula for potential

For 450 V

$V=\dfrac{kQ}{r}$

$450=\dfrac{kQ}{r}$ ....(I)

For 150 V

$150=\dfrac{kQ}{r+7.2}$ ....(II)

Divided equation (I) by equation (II)

$\dfrac{450}{150}=\dfrac{\dfrac{kQ}{r}}{\dfrac{kQ}{r+7.2}}$

$3=\dfrac{(r+7.2)}{r}$

$3r=r+7.2$

$r=\dfrac{7.2}{2}$

$r=3.6\ m$

Hence, The radius of the sphere is 3.6 m.

3 0

3 years ago

Can someone pleaseeee answer this !!!!!!

LenaWriter [7]

Answer:

The person with locked legs will experience greater impact force.

Explanation:

Let the two persons be of nearly equal mass (say m)

The final velocity of an object (person) dropped from a height H (here 2 meters) is given by,

$v=\sqrt{2gH}$

( $g$ = acceleration due to gravity)

which can be derived from Newton's equation of motion,

$v^2=u^2+2aS$

Now, the time taken (say $t$ ) for the momentum ( $mv$ ) to change to zero will be more in the case of the person who bends his legs on impact than who keeps his legs locked.

We know that,

$Force=\frac{\Delta(mv)}{t}$

Naturally, the person who bends his legs will experience lesser force since $t$ is larger.

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3 years ago

If you were in a spaceship watching a ball hover at rest (inside the spaceship) in mid-air, and the spaceship suddenly began rap

USPshnik [31]

Answer:

It will still hover until the spaceship "hits" or exerts a force on it.

Explanation:

Remember, if there is no net force, there is no acceleration or movement.

In this case, our ball is hovering in the spaceship, and in space, we can assume there is no $F_g$ , and we can assume there is no $F_N$ , nor no forces acting against it.

So, the ball would not move.

However, once the spaceship starts accelerating, the ball would still hover until the spaceship exerts a force on it.

This is because of the same thing as explained above, no forces acting on it, therefore, no acceleration.

Think about it this way.

Imagine you jumped up, then someone threw a ball at you. Now let's imagine you can't move until you hit the floor, meaning that in an ideal situation only $F_g$ is acting on you. Now again, let's imagine time slows really down for you, but not the ball. Before the ball comes and hits you, you are "hovering" like a ball. But after the ball hits you, you move a little because the ball exerted a force on you.

If you did not understand what I meant above, just forget about it, and think about the fact that if there is a Net force (all the force values added up), then there is acceleration and movement.

4 0

2 years ago