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andrezito [222]

2 years ago

12

An 800 N man stands on a scale in a motionless elevator. When the elevator begins to move, the scale

1 answer:

DENIUS [597]2 years ago

3 0

Answer:

Net force = 800 – 650

= 150 N

150 = (800 ÷ 9.8) a

a = 1470 ÷ 800

= 1.8375 m/s^2, downwards

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Two parallel wires carry a current I in the same direction. Midway between these wires is a third wire, also parallel to the oth

Luda [366]

Answer:

Force is repulsive hence direction of force is away from wire

Explanation:

The first thing will be to draw a figure showing the condition,

Lets takeI attractive force as +ve and repulsive force as - ve and thereafter calculating net force on outer left wire due to other wires, net force comes out to be - ve which tells us that force is repulsive, hence direction of force is away from wire as shown in figure in the attachment.

4 0

2 years ago

Read 2 more answers

What momentum does a 70 kg person running 10m/s (a fast sprint) have ?

gogolik [260]

Momentum = (mass) x (speed)

Momentum = (70 kg) x (10 m/s)

<em>Momentum = 700 kg-m/s</em>

8 0

2 years ago

Your 64-cm-diameter car tire is rotating at 3.3 rev/swhen suddenly you press down hard on the accelerator. After traveling 250 m

umka21 [38]

Answer:

0.76 rad/s^2

Explanation:

First, we convert the original and final velocity from rev/s to rad/s:

$v_o = 3.3\frac{rev}{s} * \frac{2\pi rad}{1rev} =20.73 rad/s$

$v_f = 6.4\frac{rev}{s} * \frac{2\pi rad}{1rev}=40.21 rad/s$

Now, we need to find the number of rads that the tire rotates in the 250m path. We use the arc length formula:

$D = x*r \\x = \frac{D}{r} = \frac{250m}{0.64m/2} = 781.25 rads$

Now, we just use the formula:

$w_f^2-w_o^2=2\alpha*x$

$\alpha =\frac{w_f^2-w_o^2}{2x} = \frac{(40.21rad/s)^2-(20.73rad/s)^2}{2*781.25rad} = 0.76 rad/s^2$

6 0

2 years ago

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The 2.5-Mg van is traveling with a speed of 100 km>h when the brakes are applied and all four wheels lock. If the speed decre

Andrew [12]

Answer:

0.34

Explanation:

2.5 Mg = 2500 kg

The change in speed from 100 km/h to 40 km/h is

$\Delta v = 100 - 40 = 60 km/h = 60 * 1000 / (60 * 60) = 16.67 m/s$

The deceleration caused by friction force is the change in speed per unit of time

$a = \Delta v / \Delta t = 16.67 / 5 = 3.33 m/s^2$

Using Newton 2nd law we can calculate the friction force that caused this deceleration:

F = ma = 2500 * 3.33 = 8333 N

Let g = 9.8m/s2. Friction force is the product of normal (gravity) force and friction coefficient

$F = mg\mu$

$8333 = 2500*9.8\mu$

$\mu = \frac{8333}{2500 * 9.8} = 0.34$

4 0

2 years ago

What is the change in potential energy of an energetic 65 kg hiker who makes it from the floor of death valley to the top of mt.

Umnica [9.8K]

Check the attached file for the answer.

7 0

2 years ago