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2 years ago

A student wishes to work out how much power she uses to lift her body when climbing a

Physics

1 answer:

Bess [88]2 years ago

4 0

Answer

i'm not 100% sure but 1764

Explanation:

Work done = gravitational potential energy

Gravitational potential energy = mass(kg) × height(m) × gravitational field strength(N/kg)

We can assume that the student is on earth so the gravitational field strength is 9.8N/kg

So work done = 60 × 3×9.8

=1764

(if you need help calculating power but if you do just divide your answer by 12 and you will get 147)

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Stand on a bathroom scale on a level floor, and the reading on the scale shows the gravitational force on you, mg. If the floor

kari74 [83]

Answer:

The angle introduces an error on the mesure of the weight

Explanation:

Weight and Normal Forces

When an object is resting on a horizontal surface, its weight is directed downwards and the normal force has the same magnitude and opposite direction, i.e. directed upwards. When some angle α exists between the surface and the horizontal plane, the scale keeps 'feeling' the Normal force, but it's not equal to the weight anymore, but to the perpendicular component of the weight to the surface where the scale is placed. It can be found that the component of the weight is m.g.cosα

If, for example $\alpha=10^o$ , the real measure is

$m.g.cos 10^o=0.985(mg)$

That is, 98.5% of the correct weight. So it's important to measure weight on horizontal surfaces

7 0

3 years ago

To view an interactive solution to a problem that is similar to this one, select Interactive Solution 7.24. A 0.0146-kg bullet i

Vinil7 [7]

Answer:

0.25223 seconds.

Explanation:

$m_1$ = Mass of bullet = 0.0146 kg

$m_2$ = Mass of block = 2.55 kg

v = Combined velocity

$u_1$ = Velocity of bullet = 816 m/s

g = Acceleration due to gravity = 9.81 m/s²

As linear momentum is conserved

$m_1u_1 + m_2u_2 =(m_1 + m_2)v$

Now $u_2=v$ as the block (with the bullet in it) reverses direction and rises,

$m_1u_1 + m_2v =(m_1 + m_2)v\\\Rightarrow m_1u_1=(m_1 + m_2)v-m_2v\\\Rightarrow 0.0146\times 816=(0.0146 + 2.55)v-(-2.55v)\\\Rightarrow 11.9136=2.2646v+2.55v\\\Rightarrow 11.9136=4.8146v\\\Rightarrow v=\frac{11.9136}{4.8146}\\\Rightarrow v=2.47447\ m/s$

Equation of motion

$v=u+at\\\Rightarrow t=\frac{v-u}{a}\\\Rightarrow t=\frac{2.47447-0}{9.81}\\\Rightarrow t=0.25223\ s$

The time t is 0.25223 seconds.

3 0

3 years ago

What is the color of the stars with the highest surface temperature and what is the color of the stars with the lowest surface t

fenix001 [56]

It is a basic color like whit or yellow

5 0

3 years ago

Read 2 more answers

An 80kg parachutist jumps out of an airplane. Neglecting air friction, how fast will he be going after a 10 second free fall?

olganol [36]

If he is jumping you are adding force which means that you will be falling twice as fast

6 0

3 years ago

In a game of egg-toss, you and a partner are throwing an egg back and forth trying not to break it. Given your knowledge of mome

lutik1710 [3]

F=dP/dt. So you want the momentum to change as slowly as possible in time to minimize the force. So as you catch the egg, let your hand move backward with it for awhile, slowly bringing it to a stop. If you hold your hand steady when you catch it the force due to the impact could break it.

3 0

3 years ago