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1 year ago

What was the vertical component of her acceleration during push-off? the positive direction is upward?

1 answer:

5 0

The answer of these two problems are : A) a = (F-W)/m = (100-500)/500/g = 9.8*500/500 = +9.8 m/sec^2 B) a1 = +9.8-g = 0

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A screwdriver is used to pry the lid off a paint can. The resistance arm is 0.5 cm long and the effort arm is 20 cm long. What i

Lunna [17]

Answer:

Explanation:

Mechanical advantage = effort arm / load arm

MA = 20 cm / 0.5 cm

MA = 40

4 0

2 years ago

A glider of mass 0.240 kg is on a frictionless, horizontal track, attached to a horizontal spring of force constant 6.00 N/m. In

Sveta_85 [38]

Answer:

$E_M=0.0492J$ .

Explanation:

The mechanical energy of the system will be the kinetic energy plus the elastic potential energy: $E_M=K+U_e$ .

We know that the equation for the kinetic energy is $K=\frac{mv^2}{2}$ , where m is the mass of the object and v its velocity.

We know that the equation for the elastic potential energy is $U_e=\frac{k\Delta x^2}{2}$ , where k is the spring constant and $\Delta x$ the compression (or elongation) respect to equilibrium.

So for our values we have:

$E_M=K+U_e=\frac{mv^2}{2}+\frac{k \Delta x^2}{2}=\frac{(0.24kg)(0.4m/s)^2}{2}+\frac{(6N/m)(0.1m)^2}{2}=0.0492J$ .

6 0

2 years ago

A 5-kg concrete block is lowered with a downward acceleration of 2.8 m/s2 by means of a rope. The force of the block on the Eart

maksim [4K]

When the body touches the ground two types of Forces will be generated. The Force product of the weight and the Normal Force. This is basically explained in Newton's third law in which we have that for every action there must also be a reaction. If the Force of the weight is pointing towards the earth, the reaction Force of the block will be opposite, that is, upwards and will be equivalent to its weight:

F = mg

Where,

m = mass

g = Gravitational acceleration

F = 5*9.8

F = 49N

Therefore the correct answer is E.

5 0

1 year ago

The spectrum of Star A has an absorption line of hydrogen at 660.0 nm. The spectrum of Star B has an absorption line at 666 nm.

rjkz [21]

Answer:

The stars are moving away from us.

Explanation:

The observed wavelengths of hydrogen transition for stars A and B (660.0 nm and 666 nm respectively) are greater than that observed in the laboratory (656.2 nm). The observed long wavelengths for the stars means that the light from the stars is red-shifted.

According to the Doppler effect, red-shifted light means that the source is moving a way from the observer; therefore, we arrive at the conclusion that the stars A and B are moving away from us.

6 0

1 year ago

A 150-N box is being pulled horizontally in a wagon accelerating uniformly at 3.00 m/s2. The box does not move relative to the w

Zepler [3.9K]

Answer:

Frictional force, F = 45.9 N

Explanation:

It is given that,

Weight of the box, W = 150 N

Acceleration, $a=3\ m/s^2$