A child observes a caterpillar walking on a window sill. The caterpillar walks 18 cm to the left, then 6 cm to

At a certain location, the horizontal component of the earth's magnetic field is 2.5 × 10−5 T, due north. A proton moves eastwar

Bogdan [553]

Answer:

v = 4.10 10⁻³ m / s

Explanation:

For this exercise we will use Newton's second law where the force is magnetic

F -W = m a

As the field is directed to the north and the proton to the east, using the rule of the right hand the force is vertical upwards, the force balances the weight the acceleration is zero

F = W

q v B = m g

Let's calculate the speed

v = m g / (q B)

v = 1,673 10⁻²⁷ 9.8 / (1.6 10⁻¹⁹ 2.5 10⁻⁵)

v = 4.10 10⁻³ m / s

7 0

4 years ago

A building is being knocked down with a wrecking ball, which is a big metal sphere that swings on a 15-m-long cable. You are (un

Charra [1.4K]

Answer:

1.9 s

Explanation:

We are given that

Length of cable=l=15 m

We have to find the time you have to move out of the way.

We know that

Time period,T= $2\pi\sqrt{\frac{l}{g}}$

Where g= $9.8m/s^2$

By using the formula

$T=2\pi\sqrt{\frac{15}{9.8}}$

$T=2\times 3.14\times \sqrt{\frac{15}{9.8}}=7.77 s$

Time you have to move out

$t=\frac{T}{4}=\frac{7.77}{4}=1.9 s$

Hence,time you have to move out of the way=7.77 s

6 0

4 years ago

An incompressible fluid flows steadily through two pipes of diameter 0.15 m and 0.2 m which combine to discharge in a pipe of 0.

QveST [7]

Answer:

Average velocity = 1.835 m/s

Explanation:

Detailed explanation and calculation is shown in the image below

3 0

3 years ago

An electric motor spins at 1000 rpm and is slowing down at a rate of 10 t rad/s2 ; where t is measured in seconds. (a) If the mo

REY [17]

Answer:

a) The tangential component of acceleration at the edge of the motor at $t = 1.5\,s$ is -1.075 meters per square second.

b) The electric motor will take approximately 3.963 seconds to decrease its angular velocity by 75 %.

Explanation:

The angular aceleration of the electric motor ( $\alpha$ ), measured in radians per square second, as a function of time ( $t$ ), measured in seconds, is determined by the following formula:

$\alpha = -10\cdot t\,\left[\frac{rad}{s^{2}} \right]$ (1)

The function for the angular velocity of the electric motor ( $\omega$ ), measured in radians per second, is found by integration:

$\omega = \omega_{o} - 5\cdot t^{2}\,\left[\frac{rad}{s} \right]$ (2)

Where $\omega_{o}$ is the initial angular velocity, measured in radians per second.

a) The tangential component of aceleration ( $a_{t}$ ), measured in meters per square second, is defined by the following formula:

$a_{t} = R\cdot \alpha$ (3)

Where $R$ is the radius of the electric motor, measured in meters.

If we know that $R = 7.165\times 10^{-2}\,m$ , $\alpha = 10\cdot t$ and $t = 1.5\,s$ , then the tangential component of the acceleration at the edge of the motor is:

$a_{t} = (7.165\times 10^{-2}\,m)\cdot (-10)\cdot (1.5\,s)$

$a_{t} = -1.075\, \frac{m}{s^{2}}$

The tangential component of acceleration at the edge of the motor at $t = 1.5\,s$ is -1.075 meters per square second.

b) If we know that $\omega_{o} = 104.720\,\frac{rad}{s}$ and $\omega = 26.180\,\frac{rad}{s}$ , then the time needed is:

$26.180\,\frac{rad}{s} = 104.720\,\frac{rad}{s}-5\cdot t^{2}$

$5\cdot t^{2} = 104.720\,\frac{rad}{s}-26.180\,\frac{rad}{s}$

$t^{2} = \frac{104.720\,\frac{rad}{s}-26.180\,\frac{rad}{s} }{5}$

$t = \sqrt{\frac{104.720\,\frac{rad}{s}-26.180\,\frac{rad}{s} }{5} }$

$t \approx 3.963\,s$

The electric motor will take approximately 3.963 seconds to decrease its angular velocity by 75 %.

8 0

3 years ago

6. If a bicyclist, with initial velocity of zero, steadily gained speed until reaching a final velocity of 39m/s, how far would

Bezzdna [24]

Answer:

175 m

Explanation:

The average velocity for constant acceleration is the average of the beginning and ending velocities. That is (0+39)/2=19.5 m/s. If the bicyclist rides for 9 seconds, the distance traveled is ...

(9 s)(19.5 m/s) = 175.5 m

She would travel 175.5 meters in that time.

7 0

4 years ago