A car changes its velocity from 40.0 m/s to -5.0 m/s in 5.0 seconds what was the car average acceleration

An archer shoots an arrow 75 m distant target; the bull's-eye of the target is at the same height as the release height of the a

Liono4ka [1.6K]

Answer:

$16.25^{\circ}$

Explanation:

R = Horizontal range of projectile = 75 m

v = Velocity of projectile = 37 m/s

g = Acceleration due to gravity = $9.81\ \text{m/s}^2$

Horizontal range is given by

$R=\dfrac{v^2\sin2\theta}{g}\\\Rightarrow \theta=\dfrac{\sin^{-1}\dfrac{Rg}{v^2}}{2}\\\Rightarrow \theta=\dfrac{\sin^{-1}\dfrac{75\times 9.81}{37^2}}{2}\\\Rightarrow \theta=16.25^{\circ}$

The angle at which the arrow is to be released is $16.25^{\circ}$ .

4 0

3 years ago

Why is an element considered a pure substance?

anastassius [24]

Answer:

An element is a pure substance and is made of only one type of atom.

Explanation:

It cannot be broken down into a simpler substance.

3 0

3 years ago

A 5.0-m long, 12-kg uniform ladder rests against a smooth vertical wall with the bottom of the ladder 3.0 m from the wall. the c

Semmy [17]

First establish the summation of the forces acting int the ladder

Forces in the x direction Fx = 0 = force of friction (Ff) – normal force in the wall(n2)

Forces in the y direction Fy =0 = normal force in floor (n1) – (12*9.81) –( 60*9.81)

So n1 = 706.32 N

Since Ff = un1 = 0.28*706.32 = 197,77 N = n2

Torque balance along the bottom of the ladder = 0 = n2(4 m) – (12*9.81*2.5 m) – (60*9.81 *x m)

X = 0.844 m

5/ 3 = h/ 0.844

H = 1.4 m can the 60 kg person climb berfore the ladder will slip

7 0

3 years ago

Read 2 more answers

Gravity is ____________________ to the distance between and difference in mass between two objects

olga55 [171]

Gravity is proportional to its mass and distance between it and another object

3 0

3 years ago

Read 2 more answers

At what position in its elliptical orbit is the speed of a planet a maximum? when it is closest to the sun when it is farthest f

Phantasy [73]

Answer:

1.when it is closest to the sun

2.when it is midway between its farthest

Explanation:

According to the law of Kepler's

T ² ∝ r³

T=Time period

r=semi major axis

We also know that time period T given as

$T=\dfrac{2\pi r}{v}$

v=Speed

$v=\dfrac{2\pi r}{T}$

$v\alpha \dfrac{r}{T}$

$v^2\alpha \dfrac{r^2}{T^2}$

$v^2\alpha \dfrac{r^2}{r^3}$

$v^2\alpha \dfrac{1}{r}$

$v\alpha \dfrac{1}{\sqrt{r}}$

So we can say that ,when r is more then the speed will be minimum and when r is low then speed will be maximum.

7 0

3 years ago