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An object with more mass has more kinetic energy than an object with less mass, if both objects are moving ____.

suter [353]

An object with more mass has more kinetic energy than an object with less mass, if both objects are moving at the same speed. (c)

6 0

3 years ago

Read 2 more answers

Friction force depends on (select any of the following)

igor_vitrenko [27]

-the contact force

-weight of an object

-the surfaces in contact (coefficient of friction).

these are what I think are the answer

4 0

3 years ago

When you skid to a stop on your bike, you can significantly heat the small patch of tire that rubs against the road surface. Sup

Lunna [17]

Answer:

$E=14.4\ J$

Explanation:

In this case the kinetic energy of the bike is converted into the heat energy between the area of contact of tyre and the road. This happens due to the work done by the frictional force between the surface to stop the relative motion between the road and the tyre.

Given:

normal force on the rear tyre, $N=45\ N$

(as given in the question that the rear tyre supports half the combined weight of the bike and the rider.)

distance dragged while stopping the tyre, $s=0.4\ m$

coefficient of kinetic friction between the surfaces, $\mu=0.8$

Now, frictional force between the surfaces:

$f=\mu.N$

$f=0.8\times 45$

$f=36\ N$

Now, the work done by the kinetic friction:

$W=f.s$

$W=36\times 0.4$

$W=14.4\ J$

According to the energy conservation this amount of energy is converted into thermal energy between the surfaces in contact, i.e. road and the tyre.

5 0

3 years ago

A soccerball is kicked straight out from a hill at 15 m/s and lands 42m away. how tall is the hill

ozzi

Answer:

The height of the hill is, h = 38.42 m

Explanation:

Given,

The horizontal velocity of the soccer ball, Vx = 15 m/s

The range of the soccer ball, s = 42 m

The projectile projected from a height is given by the formula

S = Vx [Vy + √(Vy² + 2gh)] / g

Therefore,

h = S²g/2Vx² (Since Vy = 0)

Substituting the values

h = 42² x 9.8/ (2 x 15²)

= 38.42 m

Hence, the height of the hill is, h = 38.42 m

4 0

4 years ago

Two floors in a building are separated by 4.1 m. People move between the two floors on a set of stairs. (a) Determine the change

Ket [755]

Answer:

a) The change in potential energy of a 3.0 kilograms backpack carried up the stairs.

b) The change in potential energy of a persona with weight 650 newtons that descends the stairs is -2665 joules.

Explanation:

Let consider the bottom of the first floor in a building as the zero reference ( $z = 0\,m$ ). The change in potential energy experimented by a particle ( $\Delta U_{g}$ ), measured in joules, is:

$\Delta U_{g} = m\cdot g\cdot (z_{f}-z_{o})$ (1)

Where:

$m$ - Mass, measured in kilograms.

$g$ - Gravitational acceleration, measured in meters per square second.

$z_{o}$ , $z_{f}$ - Initial and final height with respect to zero reference, measured in meters.

Please notice that $m\cdot g$ is the weight of the particle, measured in newtons.

a) If we know that $m = 3\,kg$ , $g = 9.807\,\frac{m}{s^{2}}$ , $z_{o} = 0\,m$ and $z_{f} = 4.1\,m$ , then the change in potential energy is:

$\Delta U_{g} = (3\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (4.1\,m-0\,m)$

$\Delta U_{g} = 120.626\,J$

The change in potential energy of a 3.0 kilograms backpack carried up the stairs.

b) If we know that $m\cdot g = 650\,N$ , $z_{o} = 4.1\,m$ and $z_{f} = 0\,m$ , then the change in potential energy is:

$\Delta U_{g} = (650\,N)\cdot (0\,m-4.1\,m)$

$\Delta U_{g} = -2665\,J$

The change in potential energy of a persona with weight 650 newtons that descends the stairs is -2665 joules.

5 0

3 years ago

Plz help me to find my science matching... ​

Plz help me to find my science matching...