An elephant travels 16metes to the left in 20s, what is the average velocity?

What is the net force on a truck if the force of friction is 31 N and the force of the engine is 79 N?

Evgen [1.6K]

Answer:

Fr = 48 [N] forward.

Explanation:

Suppose the movement is on the X axis, in this way we have the force of the engine that produces the movement to the right, while the force produced by the brake causes the vehicle to decrease its speed in this way the sign must be negative.

∑F = Fr

$F_{engine}-F_{brake} =F_{r}\\F_{r}=79-31\\F_{r}=48[N]$

The movement remains forward, since the force produced by the movement is greater than the braking force.

3 0

2 years ago

Hi, please just say the Letter (A,B,C,D,E)

bija089 [108]

The letter that answers this question correctly is E .

4 0

2 years ago

A 544 g ball strikes a wall at 14.3 m/s and rebounds at 14.4 m/s. The ball is in contact with the wall for 0.042 s. What is the

Nezavi [6.7K]

Answer:

$F = 371.738\,N$

Explanation:

Let assume that ball strikes a vertical wall in horizontal direction. The situation can be modelled by the appropriate use of the definition of Moment and Impulse Theorem, that is:

$(0.544\,kg)\cdot (14.3\,\frac{m}{s})-F\cdot \Delta t = -(0.544\,kg)\cdot (14.4\,\frac{m}{s} )$

$F\cdot \Delta t = 15.613\,\frac{kg}{m\cdot s}$

The average force acting on the ball during the collision is:

$F = \frac{15.613\,\frac{kg}{m\cdot s} }{0.042\,s}$

$F = 371.738\,N$

3 0

3 years ago

Read 2 more answers

A bowling ball is rolling at a velocity of 56 km/h with a momentum of 130 kg-m/s. What is its

Deffense [45]

Answer:

Explanation:

Momentum

8 0

2 years ago

A coil is wrapped with 300 turns of wire on the perimeter of a circular frame (radius = 8.0 cm). Each turn has the same area, eq

MAVERICK [17]

Answer:

Approximately 18 volts when the magnetic field strength increases from $\rm 20\; mT$ to $\rm 80\;mT$ at a constant rate.

Explanation:

By the Faraday's Law of Induction, the EMF $\epsilon$ that a changing magnetic flux induces in a coil is:

$\displaystyle \epsilon = N \cdot \frac{d\phi}{dt}$ ,

where

$N$ is the number of turns in the coil, and
$\displaystyle \frac{d\phi}{dt}$ is the rate of change in magnetic flux through this coil.

However, for a coil the magnetic flux $\phi$ is equal to

$\phi = B \cdot A\cdot \cos{\theta}$ ,

where

$B$ is the magnetic field strength at the coil, and
$A\cdot \cos{\theta}$ is the area of the coil perpendicular to the magnetic field.

For this coil, the magnetic field is perpendicular to coil, so $\theta = 0$ and $A\cdot \cos{\theta} = A$ . The area of this circular coil is equal to $\pi\cdot r^{2} = \pi\times 8.0\times 10^{-2}\approx \rm 0.0201062\; m^{2}$ .

$A\cdot \cos{\theta} = A$ doesn't change, so the rate of change in the magnetic flux $\phi$ through the coil depends only on the rate of change in the magnetic field strength $B$ . The size of the magnetic field at the instant that $B = \rm 50\; mT$ will not matter as long as the rate of change in $B$ is constant.

$\displaystyle \begin{aligned} \frac{d\phi}{dt} &= \frac{\Delta B}{\Delta t}\times A \\&= \rm \frac{80\times 10^{-3}\; T- 20\times 10^{-3}\; T}{20\times 10^{-3}\; s}\times 0.0201062\;m^{2}\\&= \rm 0.0603186\; T\cdot m^{2}\cdot s^{-1}\end{aligned}$ .

As a result,

$\displaystyle \epsilon = N \cdot \frac{d\phi}{dt} = \rm 300 \times 0.0603186\; T\cdot m^{2}\cdot s^{-1} \approx 18\; V$ .

9 0

3 years ago

An elephant travels 16metes to the left in 20s, what is the average velocity?​

An elephant travels 16metes to the left in 20s, what is the average velocity?